You were in your room, crying because of the recent breakup with your exboyfriend, which wasnt really a peaceful one.

A knock on your dorm makes you raise your head from your knees, but who you finf in front of yourself isn't really who you were expecting. Katsuki.

"...Hey, i just knew about a recent breakup or whatever, from Mina, and..." He sighs in rassignment. "...I dont even know why you feel so bad, but...Tch, i ain't letting you like this, dumbass"

It was his way to show that he cared.