"Eat this."

All Might held out a long strand of hair, despite the fact that it glistened like gold in the early morning sunshine it was still hair. Hair that he was being told to eat. With all the build-up of something gained through luck and given through recognition speech that had been given moments ago, Izuku had found himself expecting something… that wasn't hair.

This led his brain to find the only rational response available to him. "Wha?"

"Oh, well you just need to eat some of my DNA, my hair seemed like the least gross option - I washed it good this morning - At least compared to my fingernail, or blood or…" All Might trailed off, his mighty cheeks flushed with an unbecoming shade of embarrassment.

"It's too different from what I imagined!" Izuku took the hair in his hand and stared at it, still unwilling to fathom the idea that he had to eat All Might's hair. Despite his obsession with All Might, this was behavior he didn't want to have on his track record.

"Too late, for all that! You need to eat it before the entrance exams!"

Well, that was all he needed to hear. The hair was inside his stomach before he could even comment that strawberry shampoo did not taste like strawberries. In fact, it just tasted like hair. The second that the hair was inside his stomach something went wrong.

Something went very very wrong.

His body felt like it was on fire, not the kind of fire that was a good kind of energy, that was there too, but the fire that was distracting him was the burning like he had eaten the spiciest food ever and was bathing in lemons after getting a thousand paper cuts.

A painful pop powerful enough to be heard as much as felt echoed from his hips as his body began to undergo a transformation. Was he turning into All Might? Was this why he had to train so hard? So that his body would be able to handle whatever this was?

"All Might?" Izuku groaned, his voice was different, softer, but still his. What on earth was happening? Shouldn't he have a manly voice if he was turning into something like All Might, tall strong and extra manly? Wait, was All Might getting taller? "Am I shrinking?"

All Might's strong hands clasped his shoulders as he reverted back to his normal mode. "Izuku, I-I'm sorry I should have known, I can't believe I forgot!"

Another pop this one closer to his jaw, and again at his hips. It felt like his abdomen was splitting open and threatening to consume him. The world began to fade to black. "But… the exams…"

For a few moments, all he felt was the wind on his face, and pain lots of pain.

XXXX

The ceiling fan spun too slow to even cause a comforting breeze as Izuku began to stir, yet it provided a wonderful distraction from the pain that his body was in. He was fairly certain everything about his body had changed. But it didn't any stronger.

But it didn't feel any weaker either, so he had that going for him.

With great effort he turned his head, desperate for some new scenery and hopefully a clock, if only to know how much of the exam he had missed. He saw a modest apartment, complete with a bookshelf, T.V., small table and most importantly a clock. It was noon. The exam was long over by now.

There went, everything. He failed to get into U.A. He failed All Might, He failed, failed, failed, failed. But most of all he failed himself.

"Dammit," Izuku placed one arm over his eyes to hold back the tears that were beginning to pool in his eyes. His voice sounded so different now, still raspy but even more unmanly and slightly broken on the inside.

He must have failed to become strong enough to handle the All Might Transformation, resulting in his body mutating some painful shell of a human being.

"Yes, thank you Nezu, again, I'm sorry for not being there in person, and are you certain recovery girl is alright with making a house call?" He heard All Might's voice enter as a door opened, he sounded like he was in his normal form. "Yes, I'll make sure to inform her the circumstances of her acceptance."

Fighting against the pain Izuku managed to sit up to see All Might carrying a bunch of bags onto a counter. He looked as depressed as he always did in that form. But who was the girl he was talking about? Did he already find a new person to pass One for All to? Well good for her, at least she wasn't a complete failure.

"What? No, I don't think it's too early to be calling her that, it's what she is now," All Might Groaned and pinched the bridge of his nose. "Look I know I messed up here, but I contacted Izuku's mother she's on her way as we speak. I just hope I got the right Sizes." Another deep sigh and the weight of the world seemed to be resting on All Might's shoulders. "Yes, I'll see you tomorrow."

Oh, good, his mom was coming to see how big of a failure her son was. Just wonderful. There was so much going on and his head was still spinning even as the pain in his body began to fade. Still, the pain of shifting even the slightest amount caused him to groan.

All Might saw this and was at his side in a moment. "Izuku, listen I'm sorry, I couldn't believe how stupid I was I completely forgot it would even do that!"

Izuku smiled, All Might was such a nice guy, even if he did find a replacement for him already. "I'm sorry for not being strong enough."

"Huh?" The World's Number One Hero looked confused. "You didn't fail… well, you actually didn't participate, I talked to the principal and he agreed to let you in, assuming you're willing to take a makeup exam."

Now it was his turn to be confused. "But… but… but, but your quirk! I couldn't take it, I was too weak after all."

All might let out a mighty sigh and smiled, "Young Midoriya, my quirk did exactly what it was supposed to do, you are the inheritor of One for All." The smile turned into a frown. "Which is part of the problem."

"Is that why everything hurts?" Though honestly, he was recovering quickly. Already he could move without gritting his teeth or groaning. It was closer to a dull ache similar to how his body felt after the first couple workouts with All Might. His body still protested against his attempt to sit upright, but he was successful.

"Kind of," All Might kneel down in front of him so that their eyes were level. "I should probably explain a bit about One for All. You see it was originally just a combination of two quirks. A quirk to pass on quirks, and a quirk to store power. However, somewhere along the line the quirk combined with another quirk, one that I forgot about."

All Might's body shifted to that of his hulking hero form. As he pressed his palm and forehead against the ground. "Forgive me Izuku I couldn't believe I forgot to tell you about the side effects of the quirk!"

Izuku simple sat in silence. He wasn't a failure, he was going to be a hero! His feet hit the ground and he stood up smiling. His body felt different, something on his chest shook, and his clothes felt loose. The shine of a mirror caught his eyes.

A girl - small, and cute, even with her well-defined muscles - stared back at him. A girl… that wasn't in the room, was staring back at him in the mirror. A look down made everything snap together.

He wasn't a failure, he was going to be a hero, he had inherited One for All, and now he was a girl. There was only one action that made sense at a time like this, passing out.

AN: So... this was a stupid idea I've had for a while, it was going to be something longer, with a romance but I'd just be rewriting canon, something I don't really enjoy. Did have an idea to have Fem All Might x Endeavor though... Anyways! I'm going to go write more The Right Temperature!