Chapter Text
First day of school and they were already at risk of being expelled!
Izuku frowned and looked out at their classmates, raising their hand.
“Sensei, do you really mean anything goes?”
Aizawa watched them with lazy eyes. “That's what I said. As long as you're using your quirk, I don't care.”
Izuku thought for a moment and then walked up to Bakugou.
“Kacchan, will you help me?” Izuku tilted their head, biting their lip. “I think that's the only way I'll actually- get anything done. I can't do it on my own. And you know how my quirk works! I need someone else for it to work! Sensei didn't say we couldn't help each other! I promise I'll be careful and I won't push it!”
Bakugou scoffed and crossed his arms, spitting to the side. “Fucking fine, useless Deku. But if we're put in the same exercise together I'm fucking splitting to get my own fucking score.”
Izuku beamed. “Thanks Kacchan!” They went in to hug him but Bakugou stopped them angrily with a hand to their forehead.
“WAIT TIL WE ACTUALLY KNOW WHEN YOU'RE GOING UP, DUMBASS!!!!”
Their classmates watched, baffled, as they began arguing back and forth until Bakugou was called up for the fifty meter dash. Izuku hopped on the balls of their feet eagerly, watching him go.
Then Izuku was called to do the test. To everyone's surprise Bakugou growled and swung a punch at them, Izuku ducked under it and launched themself into a hug towards Bakugou's chest. Midoriya clung on tight as Bakugou yelled and spun around, stomped-
And suddenly they were turning white and glowing. They quickly turned into a white blob that rose up and up and-
Oh.
A person- probably? Somebody, something stood up and the white disappeared.
A very tall kid with an insane bush of faded green hair stood where they'd been. Aizawa's eyes narrowed in on him as the rest of the class began making exclamations and yelling.
The kid reached up, stretched, he had two pairs of arms and eyes.
“WHOO!” The kid cheered, pumping his fists. “Katsuku in the HOUSE! I'M SO READY! Heck yeah- fitness test?! Oh that's so cool!” He stomped around a bit, yelling at the top of his lungs. “Heck yeah! HECK YEAH!!”
“Dude, what the hell?!” Kirishima managed to get up close to his swinging fists without getting hurt. “Is this Midoriya's quirk?!”
“YEAH!” The boy yelled, flexing all four biceps. “Izuku's quirk is Fusion! It lets him take two totally awesome people and fuse into one even cooler person! LIKE ME!” He clocked a grin at the class. “Only catch is he has to be in it, and not all fusions are as rad and awesome as me! Name's Midugou Katsuku!”
He shook Kirishima's hand forcefully, then pulled him into a side noogie to his laughter and great protest.
“If we're done here, Izuku's test is still ongoing.” Aizawa drawled sharply, watching Katsuku very, very carefully.
“YEAH, SENSEI!” Katsuku yelled and ran up to the starting line. “LET'S GO!!”
That's when they all learned something very important about Izuku's quirk. It combined the physical abilities of the people fused, and the fusion could use both their quirks.
Because Midugou braced himself firmly at the starting line and then blasted his way to the end with two of his hands, using all four arms to help combat roll to a stop.
That pretty much set the tone for the rest of the tests. Bakugou was called up for his turn separately and then when Midoriya went up they fused together and did Midoriya's test as Midugou.
The only problem was that every time they unfused in a gleam of light, it took a while. According to Midoriya “Katsuku didn't want to unfuse” and made it hard. They looked more and more tired with each fusion.
And then came the distance run.
“Bakugou, Midoriya, you're both up.” Aizawa said dully.
Izuku froze and then threw their hand up, waving frantically. “Aizawa-sensei! Wouldn't Midugou's score count as both mine and Kacchan's-”
“FUCK YOU DEKU I'M GOING TO GET MY OWN GODDAMN SCORE!”
“No.” Aizawa glared from under his hair. “Bakugou must perform his own test with his own quirk. Either find someone else to use it on or, if you're only capable of using your quirk with him, do the test by yourself and accept your score. Hurry up and figure it out.”
Izuku swallowed and looked around shyly.
“Um-” Before they could even get the question out the more excitable members of the class jumped up, waving their hands.
“Oh pick me pick me!”
“How does your quirk work?”
“Is it weird? What's it feel like?”
“N-no! I'm sorry!” Izuku cowered in on themself shyly, turning red. “K-Kacchan and I are s-super close friends, that's why we can fuse! It's diff- difficult to fuse with people I don't know!!” They covered their face, still turning redder. “A-and it's super personal and an invasion of privacy and-!” They whirled around towards Iida, who was standing off to the side and looking uncomfortable. “I'm so super sorry for fusing with you during the entrance exam, Iida! I panicked because Uraraka was going to be crushed and then you ran into me and- sometimes it just happens on accident and- I apologize deeply for the intrusion and I'd understand completely if you don't want to fuse again! But it's more likely that I can fuse with you for a second time than attempt a new fusion so please fuse with me but if you say no I will understand completely!” They bowed at the waist repeatedly.
“Wait… was that who- you were the person who rescued me during the exam?!” Uraraka exclaimed then pointed to both of them. “Or- I guess both of you were the person who saved me?!”
“Y-yes!” Midoriya squeaked.
“It's… alright, Midoriya.” Iida adjusted his glasses uncomfortably. “Afterwards I was quite upset, but having had some time to think on it, I am glad it happened, if only because it allowed me - us - to save Uraraka from being harmed by the zero-point robot.”
“Dude, what's the fusing thing feel like?” Kaminari asked, wide-eyed.
Iida looked even more uncomfortable. “It's, ah-”
“Hurry and wrap it up, we don't need to be wasting so much time on this!” Aizawa yelled from the starting line.
“Speed it the fuck up, nerds!” Bakugou cracked his knuckles.
Midoriya continued bowing to Iida. “If you don't want me to use my quirk with you I understand completely, don't feel pressured to-”
“I'll do it.” Iida blurted out.
“What?” Izuku bolted upright. “Wh-”
“Wrap it up!” Aizawa repeated.
“How do we do this?” Iida stepped closer to them awkwardly. “I recall it ah- required body contact?”
“Just-” Izuku was really turning some new shades of flustered as they stepped up and grabbed Iida's hands. “Just focus on me, and what you remember it felt like when we fused, and focus on thinking about doing the distance run. It's our goal, it's what the fusion's purpose is going to be.” Izuku took a deep breath. “And move! Do what feels natural!”
Izuku pulled on his hands as they spun sideways, bringing them into a circle. Iida's face contorted into surprise and then concentration and he for some reason picked Izuku up and then spun around and threw them up in the air. Fortunately Midoriya didn't fly very high. When they landed back against him they both turned bright white and the fusion happened.
It took almost a full minute, light glowing and changing, before the white color faded away and another four armed person stood there. They blinked, tilted their head thoughtfully, and then stretched.
“Fascinating.” They held a hand up to their chin. “I'm glad I have a calmer opportunity to realize my existence, now. Last time - the first time - was quite frantic.” They said while walking towards the start line, Aizawa sighing in relief that they were finally starting. “Uraraka!” She blinked and pointed towards herself. The fusion smiled gently and waved with one hand. “I'm very glad to see that you are alright! I'm sorry I didn't introduce myself before, my name is…” They paused and considered that. “Midoriida Tenuku. Yes.”
“A-ah thank you! Thank you for saving me!” She blushed.
“My sincere apologies for the long delay, Aizawa-sensei!” Midoriida said as they crouched at the starting line, a serious expression taking over. “I'm ready to begin now!”
Midoriida was just as fast as Iida on his own.