Everyone wasn’t that aware of how you were skipping meals or that you’d only eat small portions even though you were a big food lover. But Katsuki had a hunch something was dead wrong. And you weren’t acting what he considered normal and he’s decided he’s brushed it off enough. He was pissed he didn’t know what was going on with you so the only way to find out would be to call you out on your bullshit on why you’re not acting like yourself

It was normal of him to disregard knocking when he was fueled by determination for something. This something was to check up on you in your dorm when you didn’t come down for dinner with the rest of the class. Hell, he was the one that cooked today and he made something he knew you’d enjoy. But you not showing up just supported his hunch that something was up with you.