Chapter Text
"So what you're suggesting, damn nerd, is we switch personalities for a week?" Katsuki asked, and Izuku nodded. The blonde looked confused until he saw the tired look in Izuku's eyes and the dark eyebags almost worse than Shinsou's. He quietened down, giving the suggestion a little thought before he finally agreed.
"It'll give you some time to finally let loose and fucking relax instead of acting like you have a stick permanently up your butt, and I'll be able to let off some steam from pent up anger since the start of the year." Izuku sent him a tired smile, and the blonde agreed quickly at the suggestion of being able to let loose. They were in the last few months of their first year, childhood friends finally fixing their past and working on becoming better for each other.
Katsuki loved seeing Izuku all angry, especially with years worth of pent up anger, only being added on from the year of villains, pervert classmates and more. He sent a rather sadistic grin in Izuku's direction, who mirrored his face as they laughed. "Let's see how long it'll take until our classmates crack, Izu."
They, of course, informed Aizawa beforehand, both knowing that their homeroom teacher would have a field day with this. The underground hero immediately agreed, making a bet with both of them that if they could last the entire week without slipping up, he'll allow them to take a break from two hero training during school hours, and if they lost, he'd give them extra work for the week.
Of course, both boys were easy to convince, and Aizawa chuckled as he waited for the next day.
Katsuki woke up bright and early, groaning softly. He sat up, blinking the sleep away from his eyes as he got up to put on his uniform, rolling his eyes as the explosive blonde took out pants that didn't look like they were about to drop when he had them on before changing and for the first time, wearing the red tie. He heard a knock on his door, and he opened the door, coming face to face with Izuku.
He was tie-less, with slightly loose pants and a scowl. Katsuki's eyes widen comically, actually surprised. His brain shut down momentarily, stuttering out a good morning as the green-haired boy raised an eyebrow at him before shrugging and grabbing his hand to go to class since they were slightly late.
"Izu, you know our classmates' nicknames, right?" Katsuki asked softly, and Izuku sent him a smile with a nod before they walked towards the massive classroom door. Aizawa was already inside, texting them that he managed to keep the class from being suspicious about why they were late. Katsuki turns to Izuku, the latter sending a glare at him before flashing a smirk.
Katsuki laughs, opening the door as he walks into class. Their classmates stare at the bright smile on his face.
"Good morning! I'm sorry for being late, Aizawa-sensei." Despite being a part of their plan, Aizawa stiffened at how well Katsuki acted. The class was left in shock as he waved at Kirishima, who was stunned. Before anyone could speak up and ask what the hell was going on, Izuku slammed the door open. Mina squeaked, and in came a scowling Izuku.
"Fuckin' move it, shit nerd." Izuku shoved Katsuki aside, who nodded quickly and rushed to his seat. Izuku unceremoniously dropped his bag onto the floor, sitting down and putting his legs on the table as he raised an eyebrow at Aizawa, an indication to continue. The class couldn't believe what they saw until Aizawa explained that they were both hit by a quirk.
Izuku grinned when they heard that they would have minimal classes today since most of the staff members were out on a large scale mission. Therefore the lack of staff in the school caused the principal to call off classes. The class was thrilled; until Aizawa said they had hero training before being dismissed early. They were to change into their training uniform and meet at ground beta, the classes groaning and begrudgingly went to change.
Upon arriving at ground beta, the class stares at Izuku and Katsuki. The green-haired boy rolled his eyes, scoffing at his squad, while his friends were cooing at Katsuki. Mina hugged Katsuki, and the blonde stared at her before tears welled up in his eyes, making Kaminari, Sero and Kirishima panic.
"Aw, the stupid nerd's being a crybaby again!" Izuku taunted, eyes glinting under the sunlight as Katsuki looked at him, hurt flashing on his face. Iida reprimanded Izuku for being rude to Katsuki, but the green-haired teenager sneered at the class president. The blue-haired boy kept quiet as Izuku cursed at them, making the Bakusquad worried as Todoroki looked like he was about to combust.
"Midobro, don't tease Bakubro..." Kirishima said, and Izuku flashed a feral grin in his direction before flipping them off. Katsuki gasped, and while the rest of them believed it was because he was supposed to be like Izuku, timid, he gasped because Izuku had never mentioned that he was going to copy every single little quirk of Katsuki's, down to the pointing of middle fingers.
"That's not nice, Izucchan!" The class collectively gasped at that. Izuku rolled his eyes, telling Katsuki to fuck off and go to his loser friends and leave him alone. Uraraka looked like she would break down over Izuku becoming broken, while Mina begged Izuku to become the happy green bean he once was.
"Don't give a fuck, loser." Izuku sneered, and Katsuki nodded timidly before looking away.
"When I said I wanted a change in atmosphere, I clearly didn't mean this," Kaminari muttered, and Sero nodded solemnly. They got ready to be assigned to their partners, and the rest of the class grimaced when Aizawa paired Katsuki and Izuku together. They reluctantly left to go spar with their trusted partner while Izuku flashed a knowing smirk at Katsuki.
They ran off, leaving Aizawa confused until he realised where they were headed off to, huffing softly and a fond smile forming on his face. Katsuki raced Izuku to where they fought last time, and Izuku grinned before accepting the challenge as he activated One for All and ran. Izuku won, and he stuck out his tongue at Katsuki, where they finally started sparring. The blonde was annoyed that Izuku was so stealthy, almost list spiderman.
He saw the sparkle in Izuku's eyes as the green-haired boy evaded one of his more giant explosions, opening his mouth:
"DIE!"
Izuku punched the ground, causing it to break apart, sending Katsuki flying back. The blonde laughed, avoiding the punches. He knew that someone would find them after Izuku practically yelled his lungs out a catchphrase that was so Katsuki's brand. True to his word, Aizawa arrived with his classmates, surprised to see Izuku with a smile similar to Katsuki's that it was terrifying.
"Think you can win? Of course not! I'm the best, after all!" Izuku yelled, launching at Katsuki, who stumbled and fell as Izuku tackled him. The blonde was rendered silent, shaking in pride as he looked at Izuku.
"That's enough, you two," Aizawa said right as Izuku lifted his hand and activated One for All, the captured weapon wrapped around Izuku as Katsuki stood up, smiling shakily. Izuku yelled, thrashing around as Katsuki told him to calm down. Izuku glared at him before calming down instantly, telling Katsuki to fuck off once more.
"My baby! Are you alright?" Mina hugs Katsuki, who melts into the hug as he internally curses. Izuku watches with a huff, glaring at Aizawa to let him go, and when the teacher does so, Izuku's storming off.
"Izucchan!" Katsuki ran off, catching up to Izuku.
The class felt a headache grow as they watched Izuku threaten to flick Katsuki's head off in one go, and they grimaced when Katsuki whines that Izuku was being mean again.
In the dorms, it didn't get any better. Katsuki was nervously in a cuddle pile with his friends, eyes wide as he processed whatever the hell was currently happening as Mina excitedly talked to him, and the blonde smiled at her, feeling a lot more at ease. This idea to switch personalities to relax for the week was an excellent idea since he could finally let loose.
Izuku is yelling at Mineta in the kitchen to 'Fuck off before I punch your stupid head off until I can create grape juice', which was being recorded by Todoroki, who seemed amused at Izuku's aggression towards Mineta, something Katsuki also did whenever the short boy was talking about women in a lewd way.
Izuku was having the time of his life. No one seemed to be asking for help all the time, and he was able to finally let off some steam. Don't get him wrong, he loved helping his classmates, but he would very much love to be able to vent his anger out without destroying the training grounds and without losing it to his friends and classmates.
"Midoriya, I dare you to start a fight with Bakugou," Todoroki said, and Izuku looked at him with a pissed-off expression that the bicolour haired teenager seemed unfazed by.
"Why the fuck would I listen to your bitch-ass?" Izuku spat, turning away. Todoroki smirked, and Uraraka whispered to Jirou excitedly, alerting the majority of the girls about what would happen as they saw the way Todoroki opened his mouth.
"I see; you're just a coward then," Todoroki said bluntly, and Izuku twitched; the students near the kitchen area stared in horror as Izuku turned around, holding a knife.
"What the fuck did you just call me?!"
The Bakusquad turn to see Tokoyami and Shouji holding Izuku back as he screams 'bloody murder' and 'fuck off, icy-hot!', much to their amusement. Izuku flipped him off and told him that he was better than all of them, and Katsuki smiled in pride at how well Izuku was pulling this off.
"Oi dipshit, get the fuck up." Izuku grunts as he gestures for Katsuki to get up. The blonde looked at him in faux innocence and fear, which the green-haired teenager scowled.
"Hurry up, you fucking shit; I want to spar."
Katsuki stood up alarmingly quick, making Kaminari stare at them warily. The class watched in mild fear as Katsuki quickly followed Izuku out.
As soon as they were out and away from prying eyes and eavesdroppers, Izuku burst into laughter. Katsuki huffed a laugh, rolling his eyes as he nudged the shorter boy.
"Great performance; I rate it nine out of ten," Katsuki said with a smirk, and Izuku flashed a bright grin at him as he rambled about how hilarious it would be if they switched hero costumes, but with their size difference, it would be difficult.
Until Izuku gasped softly, taking his phone out and texting Aizawa, asking if they could get extra hero costumes with their correct measurements, Katsuki full-on laughed.
"Fuck's sake, Izuku. You're really dedicated."
"Listen, Kacchan. I've always wanted to wear your hero costume, but you'll have to wear your gauntlets while I wear my gloves because I don't want to get hurt, and I know you wouldn't want to get hurt either,"
The Wonder Duo grin at each other before heading back unscathed. Their classmates immediately yelled and asked whether they were alright, and Katsuki sheepishly rubbed the back of his head, mumbling that he had to convince Izuku to come back without sparring since it was unsupervised.
"Though it wouldn't be safe for us to spar right now, Izucchan's restless, and maybe it would've helped if he were to vent out some of his anger; maybe then he wouldn't be so angry all the time...or I could ask if he wants to spar another day so we could be supervised by Aizawa-sensei..."
"Bakugou, you're muttering," Uraraka said softly, and Katsuki looked up, apologising profusely for muttering and mumbling. Izuku laughed at the idiocy before saying Katsuki was such a huge nerd. The class watched as Kaminari hesitantly landed his hand on Katsuki's head, ruffling his hair. The blonde stiffened before relaxing completely, smiling.
The electricity user smiled widely, brightly asking Katsuki if he could pet his hair, and the blonde smiled happily and nodded, giggling softly. Izuku huffed, storming off to his room, saying he didn't want to be around 'extras'.
He grinned like a child as he walked to his room, shaking his head as Katsuki looked genuinely happy with their classmates.
This was only day one.