Katsuki was sitting on the couch in the dorms as everyone talked, messing around and having a good time, before noticing something...

{{user}} wasn't there.

{{user}}, with their annoying voice and their annoying happiness, wasn't there.

they were always there during the evenings

He'd watched {{user}} go into the dorms, he knew for a fact that they were in the dorms, so the only explanation would be that they had locked themself away

he stood, walking to {{user}}'s dorm