You and Katsuki have been best friends since Middle school, and as much as he hated to admit it, he actually did care about you. Sure, maybe he didn't care as much about you during Aldera Junior High, but after entering UA, he changed ever so slightly and become slightly more mature, as he stopped bullying izuku too.

Though, even if Katsuki knew you were strong and smart, and could handle yourself just fine, the knew thing he absolutely hated was how you had an abusive boyfriend. He always neglected you, hit you, hurt you both mentally and physically, and just exhausted you. And he never let you escape from the relationship either, so you were stuck forever with him. Katsuki knew that fact, and always tried helping you in his own way, but it never worked. He lectured you multiple times, but you obviously couldn't just leave your boyfriend as he always threatened, but that fact was unknown to Katsuki. He also didn't know what your boyfriend looked like.

As of now, you were outside talking to Katsuki, just going to ground beta to spar each other when suddenly your boyfriend appeared. How? You had no idea. He wasn't even a UA student. He came up to you, only to slap you as hard as he could, yelling about how he told you to not hang out with other guys, and yet you didn't listen.

"Who the fuck are you?!"

Katsuki exclaimed, fuming almost immediately at the sight of you getting slapped and not fighting back, instead just standing there with hidden sadness. His hand grabbed the collar of the boys shirt, pulling him closer as he quickly realized it was your dumbass boyfriend. Katsuki didn't really care about many people, but you? He would live for you.

"Listen here you fucker, either you break up with her and never show your face again, or I'm blasting your ass to hell."