Kirishima had always strived towards being manly. In his eyes, manliness was the peak of human existence.
So, he works out every day, pumping his muscles as big as he possibly can. It was a huge adrenaline boost and both guys and girls couldn't help checking him out.
"Damn, you've gotten huge over the break." Kaminari told him, reaching out a hand and squeezing his bicep. His jaw dropped as he felt the pure manliness, unable to make the slightest dent.
"Thanks bro, but I've still got a long way to go." Kirishima said, flexing his bicep. Kaminari stared at the muscular arm with an expression of awe.
"No shit, you got a long way." Bakugo said, scowling at Kirishima. "You still don't compare to me."
"You wanna go, man?" Kirishima asked, grinning confidently and placing his elbow on a nearby desk. The entire class was now watching, so Bakugo knew he couldn't back down without looking like a coward.
"Fine. Just don't cry when I break your arm." Bakugo growled, grabbing Kirishima's hand and getting into an arm wrestling position.
As Bakugo grunted with effort, Kirishima only grinned.
"Oh, have we started?" Kirishima asked, his arm not budging an inch.
It was clear which one was in charge. Clear to everyone, except for Bakugo who refused to admit it.
Bakugo struggled, his fit arm flexing to the max as he tried to move his larger classmate's arm.
"Come on, bro! You can do better than that!" Kirishima encouraged with a grin on his face. "Put some muscle into it."
"I'll show you muscle!" Bakugo grunted, managing to finally move Kirishima's arm an inch. Then another inch. And another.
The entire class looked on in shock as Bakugo slowly lowered Kirishima's arm towards the table.
"You see? This is power." Bakugo grinned, sweat running down his face. His expression changed into concern once he saw his opponent's face, however.
"You feel all confident now? You feel powerful, strong, and manly? Good, cause now it's time to show you how strong I am." Kirishima spoke, the same cocky grin still on his face.
Kirishima's bicep bulged as he started exerting strength. The veins crawled up his arm and he effortlessly pushed back Bakugo's arm, slowly defeating him, all while keeping eye contact.
"What was it you said? Real power? Yeah, I think it's clear who has the real power here." Kirishima said, slamming Bakugo's arm against the desk.
A cracking sound was heard, and at first, the class thought that they might have broken the table. Then, Bakugo let out a grunt of pain and cradled his arm.
"Oh, I'm sorry. What was it you said? Don't cry when I break your arm? Guess you should take your own advice." Kirishima said, standing up and confidently striking a double bicep pose.
The entire class gasped at the sight, staring in awe and admiration at the pumped muscles of the teenage boy.
Bakugo growled as he cradled his broken arm, trying to keep the tears of pain and humiliation from coming forth. He felt ashamed, but also strangely aroused.
"Thanks for the workout, bro." Kirishima said with a cocky grin, bouncing his large pecs. "Anytime you need to be humbled, just let me know."
"Is it me or did Kirishima grow bigger?" Tsu whispered, studying Kirishima with her observant eyes. "And isn't Bakugo smaller?"
"I don't see a difference." Uraraka said, confused.
"No. Tsu is right. Something is different. Bakugo used to be taller than Kirishima..." Momo mused, her eyes narrowing. "It could've been a growth spurt over the break, but I could've sworn that he wasn't that tall before they started arm wrestling."
The girls shared a look before they turned to study Kirishima, who was in the process of showing off his muscles for their other classmates.
Why was he suddenly so strong?