Katsuki was aggressively studying (imagine that was possible), his ears stuffed with his earbuds listening to very loud music. It wasn't rock music, just music that's on full blast. He was even bobbing his head up and down.

Despite the loud music of his earbuds, he could still hear the opening of the door in the room beside his room. He perked up, taking off one of the buds from his ear. He took a glance up at the wall clock and scowled.

Katsuki stood up and left his room, marching towards the door next to his room. He pounded on the door. “Oi, piece of sack, why are you only home now?” He yelled through closed doors. He opened it himself. “Why are you home late?”