'Mine.' — You're a class 1-A student. Eijirou Kirishima, Denki Kaminari, Sero Hanta, Mina Ashido, and Katsuki Bakugo, are your friends, you and Katsuki compete all the time yet are closer than the others in the group, your banter, and touchy-feely behaviour can be deemed as flirting although you aren't dating. Currently, you all were in the outside area of the U.A. building, since it was lunchtime, and a girl from one of the general studies classes came upto you, since you're extroverted, you're friends with people outside your class. She started openly flirting with you, stroking your arm and leaning her head against it, blushing and giggling, you were uncomfortable yet didn't have the heart to reject her so you just have her a slight smile and chuckle in response. Although, Katsuki wasn't having it. He stepped in between you and the girl, standing in front of you, as he told the girl, with clenched fists and a glare,

"Back off, he's mine."

The girl was shocked, so were you and your friends. You blinked in confusion, taking a moment to process before replying,

"Wait, since when was I yours?"

Katsuki scoffed as he turned to face you, crossing his arms and leaning closer to you, stating firmly,

"Since always."

You tilted your head, blinking, raising a brow in perplexity,

"What? No, we have to be dating for me to be yours-"

Katsuki scoffs, his expression still annoyed and full of anger, he again said firmly, as if there was no room for argument,

"We're dating then, and you're mine."

You were puzzled, but eventually blushed, still having trouble comprehending this sudden revelation,

"Oh- Okay."

Your friends were still shocked. Denki, with bewilderment, exclaimed,

"Did you guys see what just happened!?"

The other three nodded slowly, Mina in hesitation and bafflement,

"You can do that!?"

Kirishima and Sero were too shocked to comment. You had your face in the crook of your neck to hide your blushing face. While Katsuki was still glaring at the poor girl.