Looking down at the vial in his hand, Keero found himself wondering what it was he was doing with it. Though he’d been anticipating the arrival of this particular package for several months now, with it finally in front of him, Keero wasn’t sure if he even wanted to go through with it. Did he really want to spend the next two weeks as a…mouse? Even saying it out loud made him nervous. 

Why a mouse, of all things, was beyond his ability to explain to anyone rationally. But it was his fantasy and something he’d wanted to try ever since he was little. And now, as an adult, with the technology available the change one into an animal, even one as small as a mouse…

There were plenty of reasons not to do it, of course. Keero would be so small, so helpless, even though he’d be staying safely in his apartment for two weeks. He’d hardly be able to survive any number of ailments, a heart attack, having something small crush him, and a variety of dangers that were a non-issue to his human self. And with no one to watch over him…but then, who could he ever ask?

Keero’s plan was very simple. He had procured several items for his stint as a mouse in the form of bedding, toys, and meals of pellets and perishables. It was hardly a luxury hotel stay, though he wasn’t even sure if it was appropriate for a mouse to have such human-derived creature comforts. He wanted the experience to be as authentic as possible, which only served to heighten his arousal. 

Keero had to admit, regardless of how much he worried about the trials of his new life, there was something powerfully arousing about the notion of finally going through with it. He was almost tempted to touch himself then and there, though decided to hold his stamina off until he was further changed. He would have ample time to touch himself once the serum had settled in his system, after all. 

Downing it in one go, before he lost his nerve, Keero swayed there for a few moments, wondering how quickly it would take effect. That was silly, he knew. The change was supposed to take place over the course of several days, and there was little chance of him being able to detect anything right away. But, there was always the persistent eagerness that he would feel something different, something to prove that what he had purchased was not a dud. Positive user reviews be damned.

After standing there for a solid half an hour, Keero decided he was wasting his time. It would likely be some hours before anything noticeable happened, after all. He had taken the potion early in the morning, wanting to stay awake as long as possible to watch the changes starting. He figured he might as well enjoy his time as a full human before he began the descent into a non-human being for the next few weeks. Although it wasn’t going to be permanent, it was still a frightening prospect to face the unknown in an entirely non-human body. 

Regardless of that, Keero decided to watch some online videos to take his mind off the upcoming change and the subsequent repossessions. Still, it was a fool’s errand. The news carried with it no interest, for human things had little consequence for the life of a mouse. Music and entertainment held nothing for his future either. Keero would be focused on survival first, and everything else coming in second. After all, a mouse was a prey animal, and even if he would be safe here, there was no way to know for sure that he had accounted for everything that might go wrong or cause his more fragile body harm…

It was a prickling on his skin that made Keero aware that the changes were starting. It seemed to come from hair growth, focused on his chest, as though the hairs were lancing from the skin, growing patchy. He wasn’t certain about it at first; the prickling was so gentle that he could have passed it off as something else irritating the skin. But as time passed, it became hard to see the skin in some areas. Never the hairiest of men, Keero was delighted with the knowledge that he was starting to grow his very own coat! The hairs seemed to be brown, though it was hard to tell with their sparsity. 

As the minutes ticked by, the tingling over his form seemed to intensify, as though an electrical surge was present in the air. It was not something that Keero could immediately place, though it did not seem to abate no matter how much time passed. It wasn’t until he stretched a little, seeing the sleeve of his shirt out of the corner of his eyes that Keero started to question his size. Though it was hard to tell just yet, it seemed that his shirt was a little baggier than it had been hours before. A sign of his shrinking? Keero could only hope!

Heading to look at a mirror, Keero really had no measure of how much he had diminished over the course of the few hours since he had taken the potion. Recalling something from his childhood, he took out a marker and raised it above his head to make a mark on the wall. Though instead of his youth when he hoped to grow, Keero was ecstatic that he would be measuring his rate of shrinking!

As the hours passed by, Keero was slowly becoming aware that the tingling was getting worse, as though his entire body was going slightly numb. It was more akin to static making his hairs twitch, as though being risen by force. The feeling was likely a sign that more mouse hairs peppering his chest and signaling his eventual fall from humanity. In more ways than one, if the shrinking sensations were any indication!

Eventually, hunger prompted him to get up, though Keero found himself wondering what he should eat. Though a usual lunch was likely in order, could it be exciting to maybe eat like the mouse he was becoming? Maybe try one of the nutrient pellets that he had purchased? Could he do something like that? In the end, he opted for something more human, losing the nerve to try eating mouse food before he was changed enough. 

A feeling of vertigo came over him as he reached into his cupboards, as though the dimensions were beyond his familiarity. He had been in this apartment for several years now and it was beyond bizarre to have even a modicum of height decrease leave him so disorientated. How much would his worldview change when he had shrunk a significant size?

The afternoon passed slowly, Keero resisting the urge to rub the itching on his chest lest he become too familiar with it and miss the significant hair growth he was experiencing. Eventually, however, curiosity won out, and he went to play his fingers over the skin, careful of nails that seemed a little more pointed than he recalled. The hairs were patchy now, obscuring the skin in some places with their brown shade. It made him elated to know that he would soon be covered with fur, save for his hands and feet!

As he explored his body for even the most minute changes, Keero was slowly starting to find it harder to move his thumbs the more he tried. It was as though the joints were stiffening, preparing to dissolve into little more than bumps on his outer anatomy. Keero was equal parts terrified and excited to be developing such rodent-like anatomy, making him certain that the change was robbing him of his humanity in the best possible way. He wanted so much to be a mouse, and his body was physically aching with anticipation that in a few days’ time, he would get his wish! 

Wanting to keep track of the changes for posterity, Keero took a marker and outlined his hand on a piece of paper while he still had the thumbs to do so. His fingers were likely smaller than the human equivalents already, and he scolded himself for not having the foresight to do so before he started to change. But with his hands mostly human, and a mouse’s ability to hold a marker, he would be able to track the changes every few hours as his hands altered. That was until his body was smaller than the marker, of course!

It was during that effort that Keero’s attention was drawn to the fact that his nails were a bit longer than what he was expecting. Stranger still, the tips weren’t as rounded as he figured they should be, though it was hard to tell. He was sure he would experience their extension in the next few hours, becoming almost as long as the fingertips as they turned into rodent claws. How he would soon be able to hang on to surfaces and climb with them was exhilarating to anticipate, to say the least!

Finishing up the outline of his hands, putting some detail on the inside for good measure, Keero found himself wondering if the same changes were coming over his feet. His socks felt a little loose, but there was nothing other than the ever-present tingle of change that denoted any significant alterations. It gave Keero the idea to outline them as well before their eventual alteration. He would have filmed himself changing, but the alterations were happening too slowly for that. And, besides, the outlines were relatively easy to make, exciting him a little in a way that almost made him feel dirty to be documenting something so intimate. 

Taking his socks off, Keero was excited to feel that the nails on his toes were a little more pointed to match his fingernails. And, though he couldn’t see anything different in his feet, other than a decrease in their size with the rest of his body, maybe his big toe maybe seemed a little…longer? Was it always that low on the end of his foot? Was it changing? Keero could hardly tell without his humanity as a reference, prompting him to make an outline just as he had with his hands. 

Something else came to mind as he finished his drawing, one of the many things that he had forgotten to do before taking the formula. He had an order of perishables on the way, a small one to give him a variety of things to taste with a rodent’s tongue. They were due to arrive today as best as he was aware, though he hadn’t checked on the order. It should have been a non-issue, the changes not coming fast enough to really deter him from meeting the delivery driver today. Still, Keero decided to do a quick check, thinking that soon he would be far too small to work the laptop, and in fact, weigh much less than the device that had been so small compared to the human him!

At the sight of the delivery status, Keero felt his heart sink. It seemed as though his order would be a day late, that he would likely be close to halfway through his transformation before it came. Not only might he be too small to lift it, but he would also likely sport too many mouse-like features to be recognizable as human and not some sort of freak! How could he meet the delivery person like that?

Ideas rushed over his mind as Keero tried to come up with a solution. He could leave a note to have the crate dropped off, but that would not solve the problem of his inability to lift it. The only possibility would be to have his door left open, in case he was too small to open it by then, and request that the crate be left inside the door. Keero would have to hide, of course, and it was a risky request, but how else could he go about it? How fast was he going to change, anyway? ‘Two-three days’ was a vague description when he had such an important deadline to meet! 

In the end, Keero decided to leave his door open and to have the crate left on the doormat. There was always the chance that someone would get in and find him mid-change, but there was no other option to his panicked state at the time. And to that point, why was he so nervous? Was the fear that a mouse experienced all its short life creeping into his mind already or was it simply a human fear of the unknown? 

As he went back to watching TV to try and quell his nerves, another thought came to him, one that carried with it more apprehension than anything thus far. Several of the neighbors owned cats, as much as he’d seen through their windows. What if one got out and attacked him while he was in the apartment changing? He would have to do his best to shut the door before one snuck in. A chair in front of the door was the best he could think of in the moment, something to crawl up should he be too small at the time to close it himself. 

Yet even with that problem solved, the fear and nervousness did not leave Keero’s mind no matter how much he tried to distract himself. Though he had been assured of the experience’s success by reading positive reviews, he had no idea if this particular transformation would really be so safe. Mice were so small, after all, so fragile. Most of the animals that people became were much larger than a mouse, with little chance of the organ changes being fatal due to their relatively similar size to a human’s. What if one of his organs shrank faster than the rest of his body could keep up? Had a change this small ever been done? Keero had been so excited when mouse was one of the options that he didn’t even think to ask!

Moreover, what if there was something about the size difference between man and mouse that affected the normal functioning of the serum? Maybe it wouldn’t even allow him to turn back, even when the two-week limit was up. What if he was stuck as a mouse for the rest of his much shorter life? What would that be like? Keero was a little afraid to think the notion might not be as unwelcome as he thought it should be. But he really only wanted to dabble and experience the change, right? He didn’t really want to stay a mouse, he couldn’t. Curiosity be damned. 

Rubbing his body over once more, a bump at the end of his backside made Keero do a double-take. Reaching down, he was greeted with a clear protrusion sticking out about an inch from his backside. It was surprisingly sensitive, making him twitch at the realization of what it was. He was starting to grow his tail!

Eager to explore all it had to offer, Keero started to rub eagerly, wrapping his hand around the growth to try and get a sense of its development. Yet, as he did so, Keero quickly became aware that his thumb didn’t seem to wrap around it in the way he expected. A crack resonated through his wrist as his thumb became numb, Keero realizing that he couldn’t flex it from the center joint that he was used to. A similar crack in his other hand seemed to signal the same change. He was losing his thumbs, just like a rodent!

Yet, he soon found that, to his delight, his remaining fingers were just as flexible as they had been. He knew that mice had dexterous digits, maybe more so than his primate ones. And that realization had him elated, knowing that those were soon to be his own and that he would maintain such sensitivity with them, something lost in most of the other animal choices he could have made. 

It was then another idea occurred to him, one of wearing something more elastic to stay on his frame. He wanted his clothes to eventually fall off him, to expose the mouse he was becoming. But he didn’t want to lose his clothes too soon, and a smaller pair of elastic shorts he possessed would be the perfect thing to cover him. Rooting through his stuff, Keero eventually found them buried under stacks of other clothes that would do nothing for his changing form. They were far looser than he recalled them to be, though that was to be expected, given the changes slowly overcoming him. 

By now, the afternoon was waning, and Keero was prompted to head to the bathroom to see if he had shrunk further. To his shock and delight, he quickly discovered an inch was lost from his height, making him elated. He really was turning into a mouse, and the changes were coming steadily as the serum worked its way through his system. 

At that, the arousal that had been steadily playing over his mind came to a head, his cock poking at the insides of his loose shorts. It was smaller in terms of his stature, though he knew it would also soon be small relative to his body. Though his hope was that it would remain just as sensitive, and was eager to masturbate it with changing fingers regardless of how small it was!

Touching his stiff prick brought to his attention to the fact that the tips of his fingers were coarser, as though swelling out into the pads Keero knew he would eventually have. Eager to play them over his cock, Keero was delighted that their roughness felt amazing, and he stroked himself faster, eager for relief from the lust of a real-world transformation. To his embarrassment, he came quickly, blowing a modest load over his changing hand and getting it all over his cock. Not really sure if the speed was due to his intense arousal or was a facet of his soon-to-be rodent existence, it became a moot point as the pleasure was nearly enough to make him eager to cum again!

After filling out his excitedly smaller outlines of his hands and feet, Keero soon realized that the human him would be getting ready for bed soon and that he would have to work the next day. Mice, however, did not worry about such things, and besides, the elation over the change prevented him from being able to sleep. There was something exciting about sleeping a few hours at a time, to see how much it affected his shrinking body and brought him closer to the mouse he wished to be. 

Even if he wished to sleep, the persistent itching over his body would have prevented it. Keero was eager to get up to look in the mirror each time he felt the tickling of fur growth, but resisted the urge, knowing that he would not be able to tell how much he had shrunk if he checked every five seconds!

Despite his excitement over the changes, fatigue eventually caught up with him, and Keero passed out, though waking every few hours from both anticipation and the persistent prickling of fur growth. Each time he did, Keero was certain that his legs were a little shorter, having pulled up on the bed. Not only was his shrinking stature the culprit, but Keero suspected that his thighs and calves were diminishing far more rapidly than the rest of him. Keero was powerfully tempted to get up each time to measure himself, though was inevitably too tired to do so. 

Still, the idea of soon weighing little more than 30 grams was a powerful aphrodisiac, and in those periods of wakefulness, Keero was unable to resist the urge to masturbate. Though each release was rapid and provided less pleasure than he was expecting, his stamina was something else, and Keero found himself cumming at least five times over the course of the night. It did make the prickling of hair growth more intense, though the added fatigue allowed him to get the necessary shut-eye to enjoy the next day of change.

One thing his barely cognizant brain could interpret was that the stiffness in his thumbs was so intense that moving them was no longer possible. With the phantom tingles in his former digits, it was impossible to tell what state they were in without a light. Still, he was not prepared to wake and examine smaller hands with little left but nailless stubs for thumbs. They weren’t quite absent as a mouse’s would be, but they would be soon. Though Keero found the notion of losing them a little frightening, he was at least a little thankful he’d chosen a species with dexterous fingers to compensate. 

Eventually, the sun coming through the window prompted Keero to wake for the day, ecstatic that the changes would really be kicking in now. Keero proceeded to go about his morning routine, though skipped much of it, thinking a mouse would not require a shower or to brush his teeth. His dentures remained normal, for now, at least, though at this point it was more of a disappointment. Using the bathroom was a little bit of a chore, making him realize that he was about two-thirds of his former size, at least. He certainly didn’t want to accidentally fall in. Afterward, he was prompted to measure himself against the wall, partially disappointed in what was sleeping cost his awareness of the transformation but still excited by how much he’d already shrunk. 

A twitch from his backside left him reaching back with four fingers to rub against what had just been a bump before now. It reacted again with the attention, making him more excited than any experience had the right to. If he focused, he could feel it hanging there, though it was such a part of him that it seemed as natural as anything else. For the next few weeks, it would be part of his anatomy, a tail like that possessed by the mouse he was becoming. Given the size of it, it would almost certainly weigh a significant portion of his 30 or so odd grams, and Keero couldn’t be more enthused. 

Not sure if he saw the point in it, Keero opted eventually to put clothes on. Though it was not his modesty that Keero felt he was defending. Rather, it was proof of his diminished stature that he wanted to display. He had purchased some smaller, cheaper child-sized clothing that had him prepared to mark his shrinking stature. At about 4 feet tall at this point, he figured the only thing that would fit would be the child-sized elastic shorts. Though they were loose, he was able to wear them without holding them up, at least for now. How long they would last was up to the changes, but he didn’t think they would remain on him for the day. 

More annoying was the process of fitting them over his tail. Keero thought about cutting a hole in the back to alleviate the discomfort, though trying to work the scissors without thumbs was more than a little troublesome. Though his drawers were still well in reach, the disorienting sensation of reaching for something at such a different height still plagued his awareness. Eventually, his efforts to work the scissors did allow a slit large enough for the nub he now possessed and he spent about twenty minutes looking at the thing on his backside, growing ever so slightly as he wriggled it eagerly. 

The rest of his wardrobe was added with little fanfare, though even his child’s shirt was loose over his skin. It hung off him like a nightshirt, almost down to his knees. His socks were still wearable at this juncture, though even their elasticity was not sufficient to tighten as they should. Part of the reason they stayed on him was the sharpened nails that adorned his toes, something for which he was grateful, a sign of further change. 

Yet, the blanket-sized shirt came with it irritation from the itching that was constantly playing over his form. It was getting hard to justify keeping it on his frame with how frustrating it was becoming. The brown fur was still patchy but far thicker than any human hair had a right to be. And the texture was off, what he assumed a mouse’s would feel, he was certain. Still determined he needed to keep it on, Keero decided to ignore it as best he could for now, worth it for what he would soon gain. 

Though he was getting used to the sensation of hair growing all over, a sharp prickling from his cheeks made him wince, as though even thicker hairs were sprouting through. Excited as he was, Keero could hardly keep his face away from the mirror at the sight of the hairs parting the skin, thick enough that he knew they were to be his whiskers. Drawing his paws to his face, he was shocked to feel his nose twitch with more sensitivity than the human equivalent could ever possess. It was almost overwhelming, even better to know that the whiskers would guide his way even in the darkest of places, like the mouse he was becoming. 

There were more changes that his latest glance at his reflection soon made him aware of. Sitting pink on his face, Keero could tell that the base of his nose had flattened a little, the tip more pointed and the nostrils bigger than their human counterparts. Moreover, slight slits were steadily sliding up the sides of his face, ones that Keero knew would aid in his ability to smell. Sniffing deeply, he realized that the pungent scents of cleaning chemicals in the bathroom were masking other odors that he wasn’t sure of at first. There was a slightly musky scent, one that might have been his own body odor. Though it wasn’t as offensive as he might have expected, it was rather confusing, smelling only of the human self but distinct from the aroma that wafted from his current body. His level of olfactory ability was already impressive, Keero was excited to realize. Keero could even detect some of the scents from the kitchen, meals he’d eaten, and the like. What would he be able to smell when he was finished changing, so small and close to the ground?

The piercing sound of his door buzzer roused Keero from his reflection, and the reality washed over him with a cold shiver. It was most likely the delivery driver with his order. But he wasn’t ready, hardly able to hide the facial and nose changes. He supposed it could be played off as some deformity or make-up, but what would the driver say? Keero wished he could ask for his package to be left there, but the service evidently required his signature if they were buzzing to be let in. Wait, his hands! He couldn’t hold a pen, could he?

Panicking, Keero raced around his apartment, trying to find something else to cover himself with. Nothing he had would manage, and the insistent buzzer felt like a siren beckoning him to answer, lest he not be left his food. Keero had little option but to bite the bullet and headed out, trying not to trip over his socks as he entered the hallway and up the front stairs of his apartment. 

The man didn’t give Keero much of a second glance as he reached out with the order for him to sign. Hesitating for a moment, Keero eventually came up with what he thought was the perfect answer. “Sorry,” he said simply as he readied his hands, showing the lack of thumbs. Not taking the paw-like shape into account, the delivery man simply apologized and allowed him to sign his hand with his fingers as best he could. It should have been impossible to play the changes off as a physical deformity. But the human mind did do funny things sometimes, and Keero was thankful for the close call. 

Still, getting his food up to the apartment was a chore with the reduced muscle mass he now possessed. Keero struggled and eventually got his dinners into the kitchen, opening up the box and allowing the succulent smells to waft into his changed nose. Hunger came over him, be it from the changes or an increase in metabolism. Keero didn’t mind, biting into some of the nuts with gusto, starving as he had ever been. 

It was then that he realized a noticeable difference in the size of his front teeth, as though they had extended to match the ones on the bottom. Downing the rest of his nuts, Keero raced to the mirror, trying to overcome the dysphoria that came with both seeing a difference in size and shape of his altered visage. Opening lips that were already pulled back on his features, Keero was surprised to see that his teeth had taken on a noticeable change in texture and length. Their color had darkened somewhat as well, towards the orange shade that comprised most rodent dentures. He ground them against his bottom teeth a few times, though it seemed they were pulling back somewhat, reminding Keero of the necessity to chew through harder material to keep them in shape. Though, he wouldn’t be in mouse form long enough for that to matter, right…?

His clothes felt even looser at this juncture, if that was even possible, though he opted to keep them on for the moment, wanting to fall out of the cumbersome things even if he might risk tripping on them. Though, by that point, he would likely have a low enough center of balance that it would no longer be an issue. Still, his body would have to be so small then…

Lost in his reverie, Keero hardly heard the sound of his phone going off, as though he was getting a call. Making his way over to the counter where he had left the device, Keero could indeed see that he was getting a call from one of his buddies, though the reason was unclear. He had told all his friends he would be away for the time being, hadn’t he? Still, he figured he should answer to make sure he didn’t get an unwanted visit for being awol. 

Yet, the moment that he tried to work the phone was when his significantly smaller body shook with dread. His screen used a fingerprint lock, and, having not figured he would need the device, hadn’t come up with a backup plan to answer the phone. He struggled in vain to try to unlock the device, though his rodent fingers were hardly up to the task. He did have a PIN to fall back on, but by the time he managed to get it to work, the call had hung up. In the end, he had to let the call go to voice mail, without any way to playback the message that had been left for him.

Still, there was little point in worrying about something he had no control over. Besides, a twitching in his backside prompted him to reach back, annoyed once more that he didn’t have thumbs but at least thankful that he was able to feel with the hands he still possessed. His insistent tail was thicker, as best as he could tell. Heading back to the bathroom and looking into the mirror, he could see the start of brown fur poking from above his mass, though the growth was still the shade of his human skin. But he could move it, and it hung more than two inches down from his backside, looking like the size of a tail a mouse would have if said mouse was 3 and a half feet tall!

The notion of owning such an animalistic appendage made him horny all over again, and Keero reached into his pants, touching his rod with his four fingers. It was harder to get himself off that way without thumbs to masturbate his smaller penis. Still, he was able to brush his clawed fingers over it, using the sensation of his pants to help him along that final bit before getting the level of pleasure he required. Like before, the actual act took no time to complete. Mice in the wild likely didn’t have the luxury of fucking for hours at a time, though they had the stamina to mate as many females as possible, he was sure. Keero planned to use that stamina to full effect, jerking himself as much as possible, or even going down on himself when he possessed the ability to finally do so. But, for now, he was happy when in under two minutes, he came, a small amount of semen left on the inside of his shorts. Though the scent was something else, more spicy and potent to his twitching nose. The nuances of individual odors were more interesting than confusing. 

Still, it was an ache in his backside that drew Keero’s hand to reach back, thinking he was feeling more tail than what he had thought should be present. It seemed to have grown another inch, though whether an actual one or just relative to his current frame was a topic up for debate. It was clearly longer than it had been, no doubting that. Was masturbating making the changes come faster? There was certainly precedence for that. An increased heart rate in tandem with a masturbatory effort might prompt the potion in his system to accelerate the process. That, of course, gave him several questions to consider. Did he want to masturbate himself into a mouse? Hold off and slow the changes? Would he transform faster anyways as he shrank, heart rate increasing with every inch lost?

Curious if the website service would yield any answers, Keero got to his laptop, having trouble opening the device with his weakened strength. That, and the rodent paw pads made using the touchpad impossible. Plugging in his electronic mouse, a trial of its own, Keero found it troublesome to move it without the grip of his thumb. It was both exciting and dismaying how much he relied on the human appendages to live in his world, and how difficult it was to lack them. After half an hour of effort, Keero decided to stop, the effort not worth it. Besides, he thoughts somewhat grimly, he would soon find out one way or the other. 

Without his human ability to work his things, Keero was left mostly bored as the afternoon carried on. He tried again to get internet videos to play, largely more successful with his remote than he was with anything else, only his claws needed. Still, there was a powerful sense of anxiousness that Keero couldn’t shake. Whether it be the human fear of the changes or a real developing rodent fear bothering him, Keero couldn’t deny the intensity of the sensation. It was almost overwhelming, making him wonder why mice didn’t die of heart attacks more often. Wait, maybe they did? He wished he had easy access to the Internet to look!

A strange tingling from his feet had been bothering him for some time, though Keero was somewhat nervous about checking them out. He desperately wanted toe thumbs, though didn’t want to rush their development. Still, the series of soft cracks and pops emanating from both his feet in tandem seemed to indicate the reality that he was getting such appendages. Subconsciously twitching a phantom toe, Keero almost yelped out when something moved under his prompting, as though his big toe was suddenly more flexible than before. 

A feeling of elation washed over the fear as the implication of what this meant fell over him. Without his thumbs, could his feet be used to operate things? Pulling off his socks was a chore, making him wish to allow himself to let them fall off of their own accord. Though, in this instance, he could hardly wait to see what was happening to his feet. A rodent-like squeal of delight escaped his lips as he discovered his former ‘big’ toe was much thinner, matching the diameter of his other digits. Best yet were the added joints that allowed it to flex about like he really did have a thumb on each foot!

Yet, his efforts to get the toes around the remote, while impressive, were rather uncoordinated. It took him a few moments of struggle to realize that his toes were not quite flexible enough to grasp the device. Either he was not used to them yet or he needed to allow them to complete their changes. Though, by that point, he would likely be far too small to be able to use his remote anyways, so he found it a moot point. The duality of the process, he sighed to himself. 

The afternoon wore on, and with it, more changes. Keero was shrinking all the while though was not yet inclined to look in the mirror or measure himself every five minutes. He allowed himself the luxury once an hour, though the speed at which he was shrinking seemed painfully slow. When would he be the size of a mouse, damnit!

The itching of fur growth was ever-present, making him scratch the skin over his body as more and more was obscured. The fur wasn’t too soft, though it was nice enough that he was tempted to run his claws through it. It made him excited to try grooming it, though he was not quite changed enough to try it, at least, not yet. The skin itself was hard to see all over his chest and slightly chubby belly and more fur was itching outward from his treasure trail with the reality that it was soon to cover him all over. For the moment, his arms, legs, and face remained bare, though Keero figured that would not be the case for very long. 

It was through that self-exploration that Keero became aware of how much harder it was for him to move his arms around like he’d always been used to. It was as though his chest had compressed somewhat, limiting his range of motion. Though they weren’t painful, Keero could hear the uncomfortable cracks throughout his torso that signaled his sternum and shoulders were compacting on his frame, the first of the more serious structural alterations that would send him on his way to mouse-dom. At least he figured that if he changed enough, the lack of bones in his spine would allow him a greater level of flexibility than he’d had as a human. 

Eventually, it was time to measure himself again, the cracks and pops of joints and sinew enough sign he had changed enough. To his delight, he was closer to 3 feet now, indicated by the location of the mark he made on the wall. He was just over halfway there, though some aspects were more changed than others. His hands, for their part, looked like a mouse’s through and through, making it hard to even hold the marker to draw the line. Though it was shaky, he could still make the mark, a permanent sign of his journey to mouse-dom that he could keep with himself after he changed back. At least for as long as he could still hold the marker, that was!

The one lament he harbored was that with his hands in their current shape, using the marker to trace them was nigh impossible. He wouldn’t be able to do so much longer anyway, not when he was smaller than the marker. Though, he would still carry those memories every time he saw the marks, even if they didn’t go all the way to the end of his transformation!

It took another glance in the mirror that had Keero drawn to the reality that the shape of his ears was no longer in their former human configuration. An itching across them was preceded by the formation of minute hairs that were springing up along them as he watched. But the shade was darker, as though the veins were pulsating through them in an attempt to fuel their growth. It was clear there were wider as well, and Keero was sure that the muscles at the base of them were well defined. If he concentrated, Keero was almost sure he could move them, if only slightly! He was excited to try twitching them in response to a stimulus, though nothing loud enough came to his attention, for now. 

Making his way back out into the main area, Keero found himself wondering what to try next. He almost wanted the changes to come faster so he could experience things as a mouse. But an idea of what he could do now soon crept into his mind, one that appealed well to his human sensibilities. It was time to grab a beer. 

Though the size of the cans he had was a little too much for the body he possessed, Keero had to wonder if it would actually get him drunk. After all, mice were infamous for being able to hold their liquor, though not for direct reasons. Rather, their livers were larger relative to their bodies, needed for feasting on fermented grain. Keero had to try to see if he had the tolerance to go against his diminished stature!

While he could open the fridge from his vantage point, the beer was on the top shelf, not easy for him to reach, even if he did have his human hands. Like a child reaching up to grab candy from a top cupboard, Keero found he needed to get inside the fridge, to reach up and grab his goal. It was a little too cold, making him shiver and his heart race to make sure he could do so. Though his hands were insufficient to grasp the can, he was able to jury rig something with both hands as he pulled down the cold beverage. He was at least thankful the plastic wrap around them had already been removed!

To his dismay, Keero’s smaller hands, and weaker arms, seemed to have a harder time working the tab. Though, using his nails as a lever, at the risk of snapping one of them on, Keero was able to pop the tab, and, with both hands, bring the can to his lips. The taste was exquisite, far better than the cheap brew had any right to be. He figured his altered taste buds had a thing for wheat and hops! Though there was far too much liquid for him to down in one go, Keero got barely more than a slight buzz from what should have put his smaller body on its ass!

As he tipped the can to his lips, Keero couldn’t help but feel something off about his teeth. Rubbing them with sensitive fingers revealed that his incisors were much longer than they had been relative to his body. And it was almost as though his lips were extending, pulling the rest of his teeth away from them. Hell, some teeth even seemed to be missing, as though they were sinking into the gum line as he altered.

Back to the bathroom and looking in the mirror, thankful it was angled downward so that even a mouse could see himself in it, Keero opened his mouth wide, seeing a change in dentation that matched the mouse he was becoming. His canines and premolars seemed to be sinking away, leaving only the two sets of incisors in front, orange like a rodent’s. And, save for three sets of molars, which themselves took on a more sheering edge, the rest of his teeth were sinking into his skull. He was well on his way to possessing the mouth of a mouse! 

It was getting late by this juncture, and aside from also getting his rest, Keero was eager to sleep and see where the changes left him when he woke. As much as he didn’t want to miss anything, he also didn’t want to wait any longer until the next alterations overtook him. Masturbating once more for good measure, Keero soon passed out, the excitement of the past few days getting to him. 

This time it was not only the itching that kept him somewhat awake. It seemed as though his clothes were relatively larger on him, feeling more like a blanket of sorts rather than his actual clothing. The increasing thickness of his pelt made him want to take them off, though he resisted with the excitement of wanting to shrink out of them. Even though it hindered his sleep, Keero did his best to keep his clothes on for the changes, knowing that he would have all the time in the next two weeks to sleep, assuming mice needed that much!

There were other irritations that were bothering him, rousing the changing man as he rolled around in his sleep. His tail, for one, had either gotten longer, or his legs had shrunk, making it twitch against his leg. The tickling was almost maddening, though it was hard to move his damn tail in a way that allowed it to stay away from his skin. He was tempted to try and aim it towards his feet, though lacked that level of flexibility in his body to allow that. 

Another thing plaguing his thoughts was the irritation of his whiskers against the pillow, the sensitive hairs making laying on his sides as he was used to impossible. He knew mice liked soft things to make their bedding, but, clearly, they slept on their bellies. Keero resigned himself to do so, thinking it was getting into the mood of things and, at last, finally relieving that tickling of his tail against his leg. 

With that, Keero finally found some rest, though not without other irritations. He was still shrinking, he was sure. The aches in his legs were a clear sign of that. The itching of fur growth was ever-present, though starting to center over his hips and thighs. His chest felt sore as well, as though it was compressing further, making him need to readjust himself several times. He knew that his arms were becoming more restricted with the sinking of his shoulder blades, though wasn’t worried with the level that he was sure his upper body would be able to adjust. His spine, in similar fashion, felt like it was lengthening, and not just to push his tail out further, though he was sure that was happening as well. His fatigued mind knew that some of the linkages would be eliminated in his ribs to allow eventual rodent levels of flexibility, though he could move through any space big enough for simply his head. 

What he had not fully prepared for was the difficulty in standing erect he would face upon waking up in the morning. Keero almost fell over, trying to get up to stand straight. It was impossible not to have a hunch in his posture, though the position was not as uncomfortable as he might have expected. Shorter legs, however, did make it a little difficult to get down off the bed, making him have to jump to do it. His leap was a little higher, though the impact against the ground was minimal, even though it was the equivalent of jumping down off a short ledge. It was disconcerting, to say the least, though something he would have to get accustomed to. Mice were skilled jumpers, after all, so he eventually figured it would be a non-issue. 

Yet, the one thing he was not expecting was to trip over his clothes, almost falling on his face. They hung over him like billowing blankets at this juncture, and trying to walk out of them caused him to trip, though thankful that his center of gravity had adjusted with the changes. It was time to let them fall from his frame, wriggling out of them easily with how much he had altered already. 

One thing that Keero never considered until now was the changes to his voice. Naturally, the alteration to his size would denote a lighter voice, right? Could he even still talk? Opening his mouth, he tried saying “Test, Test.” For the most part, it did sound like his own voice. Was it a consequence of his altered ears more easily detecting a high-pitched cadence? There was certainly a sense of trepidation that was more noticeable in the tones than he might have expected, a sign that his ears had altered. 

The next thing he realized was that the hunger in his belly was starting to get insistent, likely the result of an increased metabolism. Keero wondered how good some of the food he had gotten would taste two days into the change. Surely, his thicker teeth could chew into some of the pellets, right? Would now be a good time to try?

Walking into the living room, it was then that Keero realized his folly. The groceries had been left on the counter, which normally wasn’t an issue. However, with his height of less than 3 feet, there was no way he could reach up there. What was the point of buying all that food if he couldn’t even get to it?! Perhaps he could push a chair close enough to reach there, though he could only hope he retained the arm strength to do so…

Keero walked out into the kitchen, looking up at his goal and pondering the best way to proceed. Part of his mind was focusing on human solutions, like the chair or a broom to reach up and grab them. Alternatively, he could open some of the bottom cupboards and try to climb his way up. Yet, as he contemplated the sensation, another impulse came over him, one that was harder to deny the more he stared at his goal. It wasn’t that far, after all…could he jump it?

Before Keero knew what he was doing, he had leaped into the air, landing on the counter without hitting his head on the ceiling. The height was almost double his current size, yet it felt like it took little effort to jump the distance. His legs, it seemed, had altered sufficiently that it was no problem to get up to somewhere so high. Though he wouldn’t be able to manage such a leap as a full mouse, it was still better than nothing and indicative of his new abilities as he continued to shrink and change. 

Before he forgot, Keero moved to push all of the fruits and veggies to the floor, not wanting to have to risk jumping up there again if he ended up shrinking too much over the next few hours. Some of his meals, like the heads of cabbage, split upon impact on the floor. But it was of little consequence to the small mouse he was to become, in fact, making it easier to get to the tastier parts of his dinners. That, and he was sure there would be leftovers and waste, something he would have to eliminate once he had changed back. Assuming he would be changed back…

Jumping down was as easy as getting up; once more, Keero felt no aches from the impact as he landed beside the various fruits and nuts that he had bought himself. The scents of food, largely ignored before now, were at the forefront of his thoughts. He was starving, as much as his increased metabolism likely needed to eat. Sinking his buck teeth into a head of cabbage, not wanting to waste it, made short work of the plant. Keero ate as quickly as he could like a man starved, his combined instincts seemingly designed for rapid feeding, lest he be exposed and left to the whims of a predator. It made sense to the human sensibilities that he would need to be quick, though Keero could scarcely imagine what possessing that mindset would truly be like. Though, he figured he would know soon enough, regardless, as the changes concluded. 

As he ate and tried to chew, it was evident that his teeth felt further apart than he recalled. He would need to check the mirror to be sure. But he at least perceived that his teeth were longer, incisors chewing away as what little molars remained made quick work of them. Of more precedence were the potent scents of the food and how much they contributed to the overall taste. Foods exploded in his mouth, his tongue tasting intricacies that he never expected in simple greens. Keero was even tempted to taste some of the pellets he had been given, though wanted to hold off just for now. He would need to eat again soon, regardless. 

Afterward, Keero simply had to go check out the changes to his face, curious as to what had happened to him overnight and not wanting to miss anything. He figured he had to at least be more than half changed at this juncture and was a little afraid of the visage he would find. Yet, his much smaller penis couldn’t help but get erect from the notion, though he wanted to wait to watch himself in the mirror to see it before he tended to those needs. His excitement only increased tenfold when he looked up, seeing himself less than 3 feet, a height he had not met since he’d been a toddler. And never with the rodent features that now played over his face! Ignoring the sensation of vertigo from the changed stature, Keero allowed himself to really enjoy the sights!

His whiskers and teeth were the most prominent features, of course. It was obvious that his lips were pulled back, giving his face a more pointed shape, though his changed nose had not yet moved to the apex of his lips. His eyes and head were mostly human, though, from the positioning of his ears, it seemed that his skull had shifted just slightly, moving them higher on his features. Ears looked like elephant’s, and were peppered with the brown hairs of the mouse he was becoming. And his own dark brown hair seemed to be altering in shade and texture to match the consistency of the fur covering him. His body had also altered with a hunched back, compressed shoulders, and a wriggling tail. Hands and feet were covered with a fine layer of hair, and chubby hips and weaker upper arms were seemingly lightly coated as well. Skin was barely visible on his chest, and even his back possessed a thick coat. All in all, he looked more mouse than man, with more shrinking to undergo. 

Keero took a few moments to really play with his features, opening his jaw wider than ever before, exposing his orange teeth and thinner tongue as he clicked his teeth together. Whipping his tail into a frenzy, he readied his backside to see that his balls had shifted slightly, right behind his butthole. Though they had not changed much yet, there was a soft layer of fur over them that excited the changing man. Even knowing how small his rodent phallus would be, Keero was elated to masturbate with it!

Yet there was another need down below, one in his bladder that struck the man becoming a mouse. Getting to the toilet, he realized that he would have to climb on top of the rim to pee. Sitting in the seat was out of the question, not with his tail in its current state. Yet, the moment he tried to jump, his slick clawed feet nearly slipped on the porcelain, leaving Keero precariously close to falling in. Using his toilet not an option, he opted to instead jump in the tub and relieve himself down the drain. At least his leaps would clear him from the rim, though he wouldn’t need to jump high with his current height. He just hoped he didn’t need to use it the other way too soon, at least not before he shrank down so it was less of an issue!

On that note, Keero became aware that he would have to make a ‘nest’ for himself, one with its own bathroom needs, bedding, and food. Mice used soft materials, sticks, and the like in a dark space to build themselves bedding. They weren’t the most sanitary of creatures, but Keero wanted a less authentic experience than that. So, a little preparation was in order before he made the nest of his bedding.

As for where to go, he figured under the bed was his best bet. He couldn’t quite get under there, not with the space between it and the floor. But, it would give his mouse-self ample room to go about his business. So, he went about the house, looking for material to use. Mouse cage bedding, sawdust and shavings, and the like, were opened and placed under the bed while he could still pull it out from the wall. Keero had considered buying himself a cage but had thought better of it. Part of the appeal was to make it around the apartment as a mouse, experiencing things from that perspective. He wasn’t going to be a pet, he was a wild animal! Albeit a minute one, but, still…

As he went back and forth looking for materials he could use, the scent of the wood at the base of his bed kept catching his attention. It was not a hunger it elicited, not exactly. Rather, there was an ache in his jaw, his teeth, specifically. It was as though he needed to, what…?

Before he knew what he was doing, Keero found himself on the base of his bed, mouth wide open and chewing at the wood with his buck teeth. Part of him thought the action to be repulsive, the treated wood likely bad for him. Yet, there was a satisfaction to the sensation on his teeth, sending such pleasurable waves through his head and body that Keero couldn’t cease the action even if he was inclined to. 

Keero couldn’t bring himself to stop until there was a sizable dent in the wood, the fragments gathered underneath him from where he’d been compelled to chew. He looked at his work with a combination of admiration and shock. There was something impressive with his ability to chew so much, and it had made him feel so good as his changing face allowed him to open his jaw. But he had done so without his own inclinations, compelled but some rodent need that defied his understanding. What did that mean? He was sure that he’d read the changes weren’t supposed to override one’s sense of self, even if there were instincts that naturally changed along with the subject’s brain. But there was so little information on transformations into small animals that it might be impossible for him to retain any humanity once he’d reached the size of a mouse. What would that be like, to be himself but trapped in such a small mind and body? It was both scary and exciting in equal measure!

Reaching up to rub the skin of his face, Keero was surprised to feel that his jaws had pushed forward slightly, as though the bones and muscles underneath had extended it. Keero couldn’t be sure from feeling alone, though if he crossed his eyes, Keero could almost see his nose stretched out to meet his upper lip. He desperately wanted to go into the bathroom to see what had changed. He was already sure he had shrunk further, given his relationship to everything in the room as he’d been working through it. 

Yet, there was one other idea that he had in mind, one that took precedence. Surely, with the alterations to his face, his voice would have to be different now, even from where it was this morning. Wondering how to approach things, he considered reciting the alphabet, wondering how his voice would be altered and excited by the prospect. 

“A, BEEEEKKK!” Keero tried to say out loud, but it seemed his voice had finally altered to elicit rodent inflections. Still, he was curious, continuing to go down the list and finding cracks in his voice that excited him. Even if he was inclined to, Keero could no longer talk like a human, no longer call for help if things went poorly. It was a truly daunting reality indeed, and one that he could not turn back from!

Keero was quickly realizing that he had very little time to gather things from a human perspective before he was a mouse entirely. Yet, as he went about his business, a certain smell entered his nose, one wafting in from under the door. It stank of a predator, of a beast that could rend him limb from limb if it was so inclined. Keero froze, not knowing what to do with that information. The powerful drives in his mind were telling him to run, to flee. It took everything Keero had not to do that in the moment!

It slowly dawned on him that the scent he was so fearful of might have been one from a cat that was regularly let out of the apartment. Though there was no chance of it getting in to attack and murder him, Keero was nonetheless experiencing the real-life fear of a mouse encountering a predator. It was the safest way he could experience such a thing, the realization that he was soon to be a prey animal in body a powerful aphrodisiac. As messed up as it was, Keero wanted to touch himself right then and there, knowing he was more mouse than man and loving it!

As he went to rub his cock between his two paws, Keero’s attention was brought to the fact that it was smaller, its surface redder and the tip somewhat pointed. It was altering from its human shape, it seemed, though was just as erect as he ever recalled. He didn’t need it to be very large, though. All he needed was its stamina and the ability to cum, making use of his proto-muzzle by the time it got to that point!

Somehow, it seemed as though his penis was firmer in his grasp than it should have been, and Keero was quick to recall that mice were one of the few mammals with a penis bone or baculum. Moving into position whenever he got hard, it was designed to hold his member firm as he became erect and mated. He could almost feel it under the skin of his penis, making him leak more at the notion that he had one. It was all he could do to hold on for any length of time, not wanting to wait to cum as he squeaked and blew his load!

Unlike his human equivalent, reaching orgasm did not fatigue him as much as he thought it would. It made sense, after all; mice needed to tend to such business quickly lest they be caught and killed. And, given the high reproductive rates of rodents, he would have to be able to cum and cum again in short order, to spill his seed in willing mates and propagate his species. And Keero planned to use that rodent’s sexual stamina to the fullest!

But for now, there was a precedence to hold back, not wanting to change himself too much too fast. There had been significant growth of fur, especially over his legs and back, that hadn’t been there the last time that he’d played over himself. Rubbing the skin with sensitive paws, Keero was delighted by the soft texture, though wanting to keep it in place. It discomforted him to rub it the wrong way, lest it felt out of sorts. And, as he did so, another compulsion came over his mind, wanting to set right the hairs. Before he could stop himself, Keero was reaching down with his tongue and buck teeth, playing them over the hairs and coating them in saliva. The motion was oddly satisfying, sending minor waves of pleasure over his body. If it felt this good, no wonder that mice groomed themselves so often!

By that point, Keero measured his height at less than 2 feet. He figured he would be too small to use the marker points on the wall much longer. Tracing his feet was largely impossible at this point, given the state of his hands. He was almost fully a mouse, though still needed to shrink at various intervals, and his anatomy had some adjustments to make before the change was over. Likely, it would take the rest of the day and finish overnight, though Keero was only able to estimate. If he masturbated, became afraid, or experienced any other stimuli, then Keero was certain he could force the change to come sooner. And part of him wanted to, excited as he was by the whole process.

By this point, his food, bedding, and even a place to deal with his waste were prepared for him under the bed. He’d had to use the bathroom again, the bathtub the only sensible place to go. At least he could use toilet paper and be still tall enough to turn on the tap to wash away his waste. It didn’t do much for the smell though, especially with the sensitivity his nostrils had. Though he figured it was all par for the course in being an animal. 

By now, Keero just wanted to change all the way and was eager to allow it to come by masturbating himself into a mouse. Though, there were still some rodent experiences he could partake in already, even though he was currently two feet tall. His closeness to the ground made smells more potent, more so than he had detected even when his nose had first changed. Of most note were the food and the cat odors he had already discovered, but everything else was slowly made aware to him as he explored his space. It was taking longer and longer for him to make it from room to room, and Keero found himself wondering how long it would take for him to traverse the vast expanse in his apartment at the size of the mouse he was steadily shrinking towards. 

The tinglings of change had been focused on his face for a while now, though it took a sudden bout of realization for him to notice that his scope of vision was growing wider. It was as though either his eyes had grown relatively to his head or that the protrusion of his face into an eventual muzzle had pushed them slightly to the sides. He could see more of the room as he moved his head, even from the perspective which he had shrunk into already. It was a little disorientating, making his eyes water as he tried harder to focus with his new vision. The assumption was that he would eventually lose the depth of focus in trade for the wider scope. Though, it was a trade-off he was willing to make to allow the final changes to overtake him. 

The increased disorientation seemed to correlate with a more rapid rate of shrinking, prompting Keero to head to the wall and make another mark. Though, it was harder to lift the maker and make a straight line with it. He figured this would be the last time he would be able to make a notation, now being just shy of 1.5 feet. It was the best he could do, though Keero had to be satisfied with it, having not the foresight to grab another implement to make sure that he could write on the wall. Oh well. It would soon be too close to the baseboard for him to see it, anyway. 

The changes to his head seemed to be accelerating, too, the last part of his body that had not altered fully. The more he stared, the more he realized that the shape of his skull was less rounded like it had sloped into his slightly-protruding muzzle. There was a very real fear that he would lose himself as he continued to shrink, his body likely smaller than any other animal that the serums were generally used to change people into. Yet, so far, save the intense fear and rodent-like instincts, there was little evidence for him to assume that would be the case. Still, Keero remained vigilant, not wanting to fully lose himself. It was one thing to be turning into a mouse but something entirely different to not even be aware of and enjoy that it had happened!

His feet, too, seemed to have altered suffuciently, the flexibility of his new ‘thumbs’ more than even his human thumbs had been able to meet. Wondering if it was easier to use the marker with them, Keero picked it up, playing his paws over them but quickly determining that his shrinking legs didn’t have the necessary strength. Though he knew that smaller beings had relatively stronger abilities given the effects of gravity, the marker was too thick for him to operate properly, to his disappointment.

Looking back into the mirror, Keero was surprised to see the level how much his face had pressed out in such short a time. His eyes looked like they should have been squeezed from the pressure, though Keero felt none of that. The whites in them were gone, and Keero saw they were almost entirely overcome with a sort of reddish brown shade. His eyes seemed beady, though Keero found, to his delight, that his vision had not altered too much from where he expected it to be. 

At this point, Keero couldn’t think of anything else to do but to play with the changes to his body, exploring his altered anatomy. It seemed as he was more flexible than before, the missing linkages in his ribs allowing s level of motion that he was not used to. He could almost reach down to touch his small penis with his muzzle, which had, by now, retreated into its newly formed sheath. Yet, at the prospect of a self-suck, Keero could feel his erection coming to fruition, rising out and bobbing up and down. Small as it was, Keero himself was tiny by now, and it was just long enough that he could reach!

Curious, Keero stuck out his tongue, tasting the tip and leaping back at the salty flavor. It was more offensive to his senses than he was expecting, and Keero found himself licking his lips for a few moments, trying to get used to it. Hardly the first time he had tasted himself, Keero was shocked at the level of complexity that the flavor gave him. It took him a moment of flicking his tongue to realize that that flavor was actually growing on him. Used to more bland flavors, it took him a few minutes to acclimate. But as soon as he had…

Eagerly, Keero reached down with his tongue, trying his best to hold his member in place with his paw-hands and teasing the tip rapidly with his tiny tongue. Though, given the flexibility with his hands and the stability provided by the baculum, it was an easy task to keep his member erect while he lapped at the tip like a tasty treat. The savory flavor had grown on him to the point he was eager to drink it down, his pulled-back lips almost close enough to suck it. Though, with buck teeth in the way, he figured that simply lapping at his penis would perhaps be the best use of his energies. 

As with his other rodent endeavors, the action brought him close to the brink of orgasm within a few moments. Yet, small snaps and the overall tingling sensations coming from his body made Keero pause for just a moment. He was shrinking even faster now, more towards the mouse he craved to be. Should he hold back, try to enjoy the feelings of shrinking for as long as possible? 

No. Keero was too close to even consider holding back. And besides, he was so close to the mouse that he would be for the next couple of weeks that he would beg to weigh 30 grams now, do whatever it took to get to that size and weight. The ache in his rounded balls made him tense up and squeak, a truly animalistic sound as he prepared to blow his load. And, in the moment, he wanted nothing more than to taste his salty essence!

A series of squeaks escaped his lips as Keero came, a few small pumps of semen that amounted to almost nothing. Still, the tangy, salty taste was divine, and he licked the tip of his cock eagerly in a bid to drink down as much as possible. The pleasure radiated down his penis, making his hips shake and shrink, at a speed that was almost dizzying. Yet, with the sheer pleasure he took in the act, there was little to be done for it as he blinked a few times, trying to get his bearings. 

Yet, as he did so, the colors in the room started to blur, as though his vision was waning. Keero closed his eyes for a few moments, trying to come to terms with what was happening. Having thought mice retained some color perception, he was shocked to notice that the world was largely in shades of black and white, though some muted browns and yellows came to his attention as he did his best to focus. It was a frightening prospect to have such vision all his life and to suddenly lose it, forced to adapt to subpar vision, the most used human sense!

That was not the only thing that he had done to himself. Keero was smaller than 1 foot now, and still shrinking if the tingling sensations were any indication. His tail thrashed in his nervousness, increased ten-fold with the loss in height and color vision. It was likely close to its final relative length, and feeling it slapping against the floor helped to calm him somewhat. He wanted, more than anything to be a mouse, and a fully-formed tail was a sure sign he was on his way to being one!

Curious as to what had happened to his voice, Keero opened his mouth, a series of panicked squeaks escaping his changed lips but nothing else. It was unnerving that he could no longer speak, but, stranger than that was the level of sounds he could elicit. Though it was not a language, not exactly, Keero was able to spend some time playing with the cadence of his voice, calling out in panic, and what he assumed was lust as he masturbated again, though not bothering to taste himself this time.

Of course, each masturbatory session forced more and more fat to receed from his body, dissolving into nothing as he shrank more and more. It was less a disturbing prospect as the notion that there was no way of knowing how he was going to get that mass back at the end of the two-week period. Would it even be possible? Or would he live the rest of a very short life as a mouse? There really was no way to know!

Of course, the physical changes were nearly over by this point, his face having pressed out, ears longed on a sloped skull. Keero kept checking every twenty minutes or so in the mirror, but, with his increased heart rate needed to sustain an animal of his size, he was shrinking all the while, his chest compressing further. Shoulders were nearly gone at this point and hips had sunk into a distended belly. Hands and feet were fully rodent, and little remained of his face in the reflect visage. Harder was to make it out in the reflection with his eyesight in his poor state!

Keero was only just starting to get used to the fact that, though he could stand up on his hind legs, his motion was now primarily that of a quadruped. As he ran back and forth, exploring his apartment from his smaller stance, a strange sight caught his eye. There seemed to be some bizarre symbols on the side of one of the boxes, ones that he was certain weren’t present before. Taking a few curious minutes to mull it over, the reality of the symbols started to sink in. He had read the words’ Fresh Produce’ on such a box before, though his perspective was much diminished by this point. But, no matter how much he stared, he could not get the words to make sense. His brain had changed so much that he could no longer read! Yet, with the loss of his vision, that reality didn’t seem to bother him as much as he figured it should. What did a mouse need to read, anyway? 

Finally, with daylight waning, Keero made the choice. He would masturbate one more time, in front of the mirror. That would surely change him most of the way, given his already increased heart rate. It took no time for him to bring his penis to erection, though he didn’t suck himself off, not this time. Keero could do that as much as he wished once he had changed, assuming he did not fully give into rodent instincts. Given his state thus far, it was unlikely. Still…

Staring in the mirror, the sight of a mostly mouse masturbating was truly a thing to behold. So was the forcing out of his face into a point, nose sat at the tip as Keero sniffed eagerly, breathing in his sex. His rounded skull slid into the muzzle fully, and any areas devoid of hair, save his hands, feet, and tail, were soon obscured by it. Hips fattened into flanks, heels were fully stretched out, and his visage was now that of a rodent. He tried to speak one more time in a human voice as he came, though, of course, only a rapid series of squeaks came out as he blew his minute testicular contents over his paws. And, naturally, there was little left of his size, losing gram after gram with each passing second. 

It did not take Keero long to determine that the changes were finally over. The constant tingling that he’d been feeling over the past three days had abated, as best as he could tell. He felt small, tiny, vulnerable in a way that defied human understanding. It was almost too much, the fear ever pervading in his mind. The world was full of threats, and his awareness of them was paramount for him to survive, to breed, to eat, and to live another day. Those thoughts were his world, and Keero took great pride in the fact that this place only smelled of him, that he was in a dark space and was safe. 

Though it was harder to see himself under the bed, Keero used his hands to rub down his body, feeling all of the hair that had covered his skin. His fingers were just as tactile as he had hoped, finding his fur soft. The texture of his bedding, too, was fine, making him certain he had made a series of good choices in their acquisition. 

Keero’s excitement defied his understanding. He was finally a mouse, all his human memories and awareness present to be able to experience it fully and remember every aspect. There was still a fear that the human part of himself might be lost, in body, at least. After all, what guarantee did he have that the changes would revert so easily once the two weeks were up? But there was nothing to be done once the serum was ingested, and he had to assume that he would regain his human life, even if he enjoyed the carefree existence of a mouse. 

At this point, there was very little for him to do but to go to sleep, tired as he was. The excitement of the day was enough to make even a creature as hyper as a mouse to be fatigued. He would have the entirety of the next few weeks to fully indulge in the life and fantasy he had always secretly harbored. But, for now, there was little to do but to pass out, closing his eyes to dream rodent dreams and to wake to an experience shared by no other human…