A wild Katsuki Bakugo appears

Izuku tried to lay low as she slipped into the 1-A classroom on their first day.

That almost went out the window when she spotted a familiar looking boy in one of the seats, leaning back precariously and his feet propped up on the desk.

Katsuki Bakugo, her childhood "friend" and school bully from back when she was quirkless. They'd not been as close since they ended up at separate high schools...Katsuki went to some elite hero-prep course, nothing like UI, far less dangerous, and less involved, but still meant for those pursuing hero careers...but they wouldn't accept Izuku any more than UI had originally.

The time apart had helped Izuku to realize how cruel Bakugo had been...she didn't hate him, but there wasn't much fondness there either...

"What're you staring at, bitch?" The blonde snarked.

Izuku doubted he recognized her. "N-nothing. Sorry"

Izuku slipped into a seat next to Tsuyu, who was already there, and she smiled.

A short while later, the class had been introduced to Shota Aizawa, and Izuku and Tsuyu saw a rather different side of him than they'd been used to.

The students were being asked to do a fitness test, but using their quirks, and the last place student was to be expelled...This was nerve-racking, but he felt with Tsuyu's quirk he could at least avoid last place...

"Alright, Izuku Midoriya, your turn." Aizawa held up a stopwatch and motioned to the starting line, and Izuku felt a sudden chill, but not due to performance anxiety.

"What the FUCK?" A loud voice broke through the crowd of students. Yeah...that's what I was worried about. Izuku sighed and turned toward the voice of Katsuki Bakugo.

"Midoriya? Deku?! Deku was a guy, but that hair...hey, you have a cousin or something with the same name?" It was clear he thought the idea was somewhat absurd, but...honestly it wasn't as weird as the truth.

"It...it's me, Katsuki." Izuku sighed.

"Bullshit, Deku was a quirkless loser who couldn't make into prep school much less U.I...and what, did you get a fucking sex change?"

"N-no, this is my quirk...it's...a long story."

"Like hell it's your..." A loud smack interrupted the shout as Tsuyu slapped Bakugo across the face.

"What the FUCK?! Who do you think you are bitch! I'll fucking kill you!" But he didn't get a chance to follow through as he was suddenly grabbed by Eraserhead's bandages and restrained, angrily struggling to reach out toward Tsuyu. "Bakugo, calm down." Aizawa shot a look at Tsuyu. "And Asui, don't do that again." Another glare at Bakugo. "I assure you that is Izuku Midoriya. I'll leave it to her what she wants to tell you beyond that...later, but you will NOT disrupt my class over this again. Am I clear?"

Bakugo glared back, but eventually nodded, and the bandages released him.

Izuku wanted put off using her quirk as long as she could, but it was inevitable her classmates would find out what she could do eventually...at least the visible parts. Well, apparently that "eventually" was going to be day 1, in the first fitness test. Of the quirks she had, Tsuyu's was the fastest, especially in a short distance, and she was able to place in the top half of the test by using it.

A barrage of questions followed from some of her classmates, which we brushed off by saying she could copy another quirk, but only use one at a time, and that there were special conditions for it to be able to work that she'd rather not get into.

All of which was true.

Monoma eyed her suspiciously at this explanation, but it wasn't until his turn that Izuku understood why...when the loud-mouthed boy sprouted engines from the backs of his legs like Iida, and easily took second place in the sprint.

Oh. Another quirk duplication quirk?! Someone to watch out for...

In the end, Midoriya placed 14th out of 20...not totally terrible, a few places below Tsuyu, who was far more practiced with her quirk...and the huge oversized breasts of Izuku's new body didn't help either.

Aizawa gave some excuse about a Rational Deception and wanting everyone to try their best to explain not expelling last place, some invisible girl named Toru, and Izuku tried to slip away as soon as possible.

Her cock had been hard through the last 2 tests, and it was only a pair of special-ordered underwear that kept it from being TOO painfully obvious to everyone around.

She needed to jerk off, badly. Tsuyu had been shooting her distracted horny looks for half an hour too, so it wasn't just her being affected. Her pheromones spiked when she was horny.

So, her stomach lurched with sudden dread when she heard a familiar voice interrupt her beeline to the bathroom. "Hey, Nerd, I want some answers."

So...Izuku explained. She wasn't sure why she bothered...the guy was a jerk, but...maybe she hoped it would placate him, and make interactions a bit less...unbearable.

So she told him...not everything, but a lot. How she'd felt about the repeated failures to make any progress toward her dream. How Bakuga had worsened that. How her mother had become a victim and given her even more reason to want to be a hero, even as she failed to find anything else she COULD be. And how she'd found a way...a risky, stupid, dangerous way, to either get a quirk...or die trying. And well, this time, for once, she'd won that gamble.

Bakugo, contrary to her expectations, didn't say a word through this explanation. Or for a long moment after, as he stared, seemingly processing everything she'd said.