“C’mon Izuku, just this once! I promise you’ll love it!” Mina Ashido pleaded, her pitch black eyes nonetheless sparkling as she practically pressed her sweating boyfriend against the wall.

“I just think it might be a little much…” Izuku Midoriya nervously tried to find a way out, knowing that the fate in store for him was inevitable. Ever since Mina had gotten hooked on personal body transformation products she had been roping in everybody she could find for quick flings, and he’d known that one day he’d be on the receiving end of it.

Unfortunately (or perhaps fortunately, depending on how it went) Mina’s tastes had inevitably turned towards the extreme, no longer willing to settle for merely blowing up her own body to enhance conventional beauty, Mina was now looking for unconventional. To this end she had acquired two particular serums intended to change the user’s very gender, springing them on a reluctant Izuku who had initially agreed to it, only to find out that the serum to change one into a musclebound hunk and the one designed to turn you into a giggling bimbo were not going to the users he had expected.

“Come ooooooon, it’s not a big deal, it’s just one day only! A quick in and out, for the experience! You know you wanna!” Mina continued to press harder.

“Okay, but do I have to be a girl?”



“That’s the best part!” Mina gleamed. “What’s the point of turning into a big muscly dude if I don’t have a princess there for me?”

“You don’t have to put it like that…” Midoriya sighed.

“Pleeeeeease? You’ll make me the happiest birthday girl in the world!” Mina brought out the birthday card, knowing that a guy like Izuku would have to give in.

“Don’t you mean birthday guy?” He joked, and Mina sensed victory, deciding to go for one last push.

“If you do this for me, on your birthday I’ll…”



Mina whispered in his ear.

“How’d you know about that?”

“I may have traded some information with Denki.” Mina winked, Izuku not being surprised about this leak.

“Well, if we’re going to do this we should start sooner rather than later.” Izuku cleared his throat quite loudly. “Everybody’s out right now, so we should be able to-”



“Alright then, me first!” Mina cheered, pulling out both vials from her back pocket. Of course she already had them on her, Izuku mentally sighed.

“Shouldn’t we get the right clothes first? I don’t think anything I own is going to fit.”



“But seeing you in guy clothes that barely fit you is half the fun! We can go shopping afterwards!” Mina grinned, Izuku shaking his head.

“I mean you! You’re taller than me, after all, and by the sound of it you’re gonna get taller.”

“Ah, right. I did prepare for this, actually!” Mina giggled as if this was no big deal that one of them would have had to walk across the dorm half naked if they’d transformed themselves first. She scurried off to her room and back, returning with both male and female clothes in a neatly folded pile, as well as her phone and a borrowed tripod.

“We’re not recording this, are we!?” Izuku went pale.

“Of course we are! I know you’re gonna want to watch it later too.” Mina said as she set it up.

“Well, you aren’t wrong, but you’d better not share it, okay?” Izuku felt like this was probably a unlikely demand, right up until Mina started stripping down to her underwear. He figured that even she probably didn’t want a video of herself like that floating around… probably. He bet that she’d be more than happy to show it to her friends, though…

“I’ll go first, I want you to see me with a clear head. Apparently you’re gonna get all weird and giggly.” Mina explained. “Until then, it’ll be man to man! We can compare sizes!”

“I’d prefer it if we didn’t do that.” Izuku winced. Mina swung both ways with equal enthusiasm, but he was going to need to become a girl to properly appreciate their new body. Probably why Mina considered this a package deal…

“Alright, here goes!” Even Mina sounded a little nervous as she popped the top on the bright blue serum, intended to be drank rather than injected.

“Are you sure it’s the right one?” Izuku checked, not that he’d mind if she mixed them up. “Just because the other one is pink doesn’t mean it’s automatically the girl one.”



“Don’t worry, they put food colouring in these things.” Mina chuckled, then downed the serum before she could hesitate again.

“Well? Is it working?” Izuku asked after a good twenty seconds of silence.

“I think so-!?” Mina finally said, her voice deepening mid-sentence. “Oh, this feels really weird!”

Her voice dropped a few octaves, and already Izuku could see her body starting to transform. Surprisingly the first thing he noticed was her shoulders widening, Mina’s particularly feminine figure easily thrown out of balance by her shoulders spreading until they were wider than her hips, already broader than Midoriya himself. He could see her arms broadening, her slim muscle thickening as her pink skin seemed to almost tighten, gaining definition and then bulging outwards. Mina noticed this and rose her arm to flex it, oohing and aahing at how her bicep seemed to bump up higher each time she pumped her arm in a showy flex.

Her abs turned rock hard and began to fill out into a six pack, and her body started to take on a lopsided triangle shape, her hips not yet thinning but her upper body thickening, her waist filling out until its pleasant curve turned into a straight line. Her chest was getting bigger from all the muscle she was piling on, but finally the last of her upper-body femininity began to give up the ghost, her bra simultaneously tightening from being stretched by everything around it that wasn’t her boobs while those themselves were fading, Mina briefly turning to the side to watch them go from large and round to small mounds to completely flat, save for impressively large pecs.

Chuckling to herself in what was now bordering on baritone, she flexed her chest with a powerful grunt and snapped her bra off entirely, giggling in an almost bizarre way that contrasted her manly torso with her still girly face that no longer fit her voice.

“You know, you could be more impressed.” She turned to Izuku with a pout, albeit one that was turning less feminine by the second. Her lips were thinning, her pointy jaw flattening then squaring out as her cheekbones began to chisel themselves into a powerful, manly form. Her nose grew slightly, enhancing her masculine appeal while her thick eyelashes thinned and her eyebrows thickened. Her hair remained the same, but her relatively short, frizzy hair gave her a similar laid-back appeal as a man as it did as a woman. She was lucky that this was the case, as were it not for her hair and distinctive pinkness, it would have been quite difficult to recognise her.

“Izuku, hand me those shorts over there! I’d better get them on before I repeat my bra trick.” Mina’s new voice boomed, Izuku rushing to do so while her hips began to flatten. She slipped the

“These are pretty comfy, maybe I should wear these more often even when I’m not having the full guy experience.” Mina mused, enjoying the sound of her own voice as he shifted around slightly. And the full guy experience she was clearly having, as she was visibly relinquishing the last of her femininity. Izuku blushed slightly as her new shorts filled out, and filled out, and filled out…

“Is that thing really necessary!?” He couldn’t help but blurt out at Mina, who laughed deeply once again.

“Hey, you’re getting huge boobs from yours, isn’t this basically the same thing?” he responded, indisputably a man now, putting his hands on his narrow hips. He now had to crane his neck downwards to look Izuku in the eye, having grown at least a head or so taller than him.



“Maybe? Not quite? I hadn’t thought about it…”

“What do you mean you hadn’t thought about it, you guys make a huge deal out of the size of these things all the time!” Mina scoffed.

“Quit pointing at it!” Izuku covered his eyes. That thing was a monster! Surely it’d split a woman in two! He attempted to focus on Mina’s thighs instead of how that was soon to be his problem, which remained roughly the same thickness but now looked like they were carved out of stone rather than pleasantly plump and soft to the touch.

“I feel like a Greek statue or something, this is great!” Mina began to freely move about now that he was fully transformed, once again admiring himself in the mirror, striking a number of stereotypical bodybuilder poses. “Agh, I should have gone bigger, I wanna look like All-Might! Or at least Endeavour! That’s what all guys wanna be like, right?”

“You’ve got that right at least.” Izuku admitted. That’d been what he’d been privately aiming for during his training, although he’d have to wait and see if he grew into it as he got older… Then, for some reason, Mina decided to plant herself down on his  knees next to the coffee table in the middle of the room.

“Hey, Izuku, get over here!” He grinned evilly, slamming his elbow down onto the table. “We’re gonna see who’s the bigger man right here, right now!”

“Um, are you sure about that?” He said as he lined himself up. “You’re not used to your body yet, and-”



“Oh please, I was born ready for this!” Mina bragged, sizing up himself compared to Izuku. He knew that Midoriya was ripped underneath his clothes, but he was like a twig compared to the sculpted body he’d obtained! What better way to flex all over him than in a classical test of strength?



“Well, if you insist…”  Izuku shrugged, taking Mina’s hand, the palm dwarfing his own. “On three… One, two… three!”

The back of Mina hand slammed against the wood almost instantly, leaving him stunned.

“One more! I wasn’t ready that time!” His hand shot back up. “And uh, give me a second to get going, I’m not used to this yet! One, two, three!”

Izuku patiently let Mina strain against his hand in their next bout for a couple of second, barely even twitching, before slamming it down.

“What the hell!? I’m way bigger than you!” Mina whined, sounding even more pathetic in his exaggeratedly masculine voice.

“Well, there’s actually a big difference between types of muscle. For example, there’s bodybuilders and then there’s power-lifters, and-”

“Whatever! Hurry up and take your serum already!” Mina shut him down as quickly as possible, grabbing the pink serum and practically shoving it into his mouth. He spluttered slightly, hurrying over to the camera and mirror.

Either by coincidence or by taking the whole thing faster than Mina, Izuku’s body seemed to change at a different rate to Mina’s, Izuku already seeing his face start to become more feminine. His lips filled out, his face thinned and rounded, and even his eyes seemed to get a little bigger. He had inherited his looks from his mother, so it for better or worse wasn’t as big of a chance as he’d expected, at least at first.

“Ooh…” Izuku’s eyes began to glaze over as a pink fog rolled into his head, making it hard to think. His mood quickly improved, as he became entranced by how his lips were continuing to grow well past feminine into distinctively puffy, gaining a button nose and eyelashes that normally couldn’t be achieved without a lot of makeup. He looked really cute, he found himself uncharacteristically thinking, giggling slightly as everything started to feel fluffy.

The fog was so thick he didn’t notice his chest puffing up until one of his buttons burst, Izuku clumsily freeing himself and letting his new breasts fall free, shoulders practically sliding inwards as his waist cinched into what would soon become a perfect hourglass. His pants grew tight while he grew light in the middle, his hands falling and fingers tracing what was now a very sensitive fold.

He already had a girly figure, thighs thickening and hips expanding, but then it exaggerated and flared out further until his waist seemed so small that it could barely conceivably carry such hefty melons up top.

Touching an inch-long nail to her lips, the now thoroughly bimbofied Izuku giggled, then giggled some more.

“Wow, you were, like, super right, I’m totes cute!”

And Mina was totes handsome, Izuku almost drooling looking at him. She wanted to just press her tits up against those abs, they were calling out to her and it was all she could do to hold herself back from jumping him then and there.

“Looks like the bimbo part is working as intended too.” Mina smiled. “Quick, Izuku, what’s thirty five times sixty-three?”



“Um, that’s, like, um…” Izuku tried to count on her fingers then gave up when she ran out. “A really big number, right? I dunno!”



“Me neither, but it was really cute watching you try.” Mina admitted. His shorts were already feeling painfully constrictive, but the best was yet to come. “Now let’s get you into this dress!”

Mina helped Izuku put on his first bra, albeit one that they had to immediately remove after Izuku whined that she couldn’t breathe in it. The panties fared better, Mina determined to enjoy the act of removing them later. The green minidress that he squeezed Izuku into just barely contained their overflowing cleavage and rocking hips, and was moulded around her bubble butt in a way that made it impossible for Mina to resist squeezing it for half the photo shoot.

“Hey, I know I’m super pretty and all, but aren’t we, like, supposed to be taking photos of the birthday boy?” Izuku pointed out.

“In a minute, in a minute…” Mina snapped photos from all angles, Izuku happily putting on her sexist pose, winking and blowing kisses to the camera. Then, when they were finally done, Mina took a few basic photos of himself.

“Can we have some real fun yet?” Izuku fluttered her eyelashes at him, and Mina completely gave in.

“I hope you didn’t like that dress too much, Izuku!” She bellowed as she practically tore it off her, pushing a heavily panting Izuku down onto the bed to enjoy the rest of their birthday…