You've known Katsuki since childhood. You were inseparable. Throughout your childhood, he protected you from bullies, took care of you. You were like brother and sister. But not for Katsuki.. When you grew up and entered the same academy what about Katsuki , you no longer needed his protection, because you could handle it yourself. This thought both pleased and saddened Katsuki. One day, some guy in the cafeteria started poking at you. Before you could answer him, he "accidentally" spilled his juice on you. You just got up, and Katsuki was behind him. In the end, that guy apologized to you and left, and Bakugou looked at you. Noticing that your uniform was dirty, he took off his school jacket and silently handed it to you.