The Atomic Hero || BNHA x Reader/OC ||

Gearing Up

You walk into one of the school's secondary gyms that students can reserve for personal training and exercise. Your braids are pulled back into a high ponytail, and since you don't have access to your hero costume outside of official school hours, you come dressed in a white cotton crop top with a black sports bra underneath and black high-rise leggings.

The gym is more of a workout room. Weights line one wall, there's a treadmill and elliptical, and a couple punching bags rest in a corner waiting to be strung up. Blue mats line the wooden floor to soften hand-to-hand takedowns.

You don't care about any of that shit, though, because there's a blond senior currently warming up in the middle of the exercise room and singing to the music that's playing through the speakers. Two other upperclassmen are also in the room, which momentarily dampens your excitement, but it rebounds quickly when you remind yourself that just standing in the same room with Mirio gives you life.

And oh my gosh, Mirio can jam hard to Lizzo.

"Oh! Oh! Hey!" the girl with silvery blue hair points at you stepping through the door and excitedly taps on Mirio's shoulder. "Look! The 1-A girl is here!"

He spins around in-beat with the music and beams. "Hey, Mari! I'm so pumped you're here!"

You're going to play the moment of him saying that over and over again like a song stuck in your head.

"Hi," you wave. Yaomomo said just to act normal when you were around Mirio. But what even is that?

"Come on in, don't be shy!" he laughs, beckoning you over. "I wanna introduce you to my friends." Mirio gestures to the excited girl. "This is—"

"Hadou Nejire," the girl answers. "You're the one with the big crazy quirk, right? You crushed those massive robots at the Sports Festival! Everybody in our class was talking about it! But then, like, why didn't you make it to the second round? I mean—"

"And this," Mirio continues smoothly as though he's used to Hadou's personality, "is Amajiki Tamaki." He gives the black-haired student who's turned partially away from you an encouraging pat on the back. "He's shy!"

"Mirio..." Amajiki mutters, "why do you have to go and say it like that?"

"Because it's true! But don't worry, Mari, he's got an insanely strong and awesome quirk. Isn't that right, Tamaki? Come on, just imagine her head is a potato."

Amajiki only slouches further. "Anyway," he says quietly, glancing in your direction but not specifically at you, his face burning bright, "H-hi."

You grin and give Amajiki another wave. He goes dark red in the face and makes his way to the wall of the gym. Hadou follows, giggling.

"Oh come on, Tamaki, you gotta be able to withstand a pretty girl! They're going to be all over you once you're a pro!"

"Why'd you two even bring me here?" he complains. Amajiki puts his forehead against the wall and stays there. "I wanna go home. I don't need to see Mirio beat up some first year."

"Psh," Mirio sputters, "I'm not gonna beat her up!"

"Yeah," you say, putting your tiny pink backpack on the ground. It has little cat ears poking up from the top. "If anything, I'm the one who's going to beat Mirio up."

Mirio's brow raises, but his smile doesn't waver. Amajiki slightly shifts so he can see you from the corner of his eye. You shrug, turning bashful, and awkwardly smile. "I mean, I'm not trying to sound cocky..."

"It's just what you believe, right?" Mirio asks. You nod. He gives you an enthusiastic thumbs up. "Well then. Let me prove you wrong!"

He stretches both arms one final time before getting into a crouched, defensive stance. Oh—wait. Like, this is happening right now?