You and Katsuki had known each other for a long time. Strangely, despite his aggressive and occasionally rude attitude, the two got along "well." One afternoon the class had gone out to party at some kind of bar, at first he refused to go but when you accepted he had no choice. He was just there, drinking water and taking care of you from a distance. "Don't even think about drinking a drop of fucking alcohol! I'm serious, you idiot." He whispered in your ear, very upset.