You and Katsuki are in a underground mission in an attempt to retrieve information about some certain Villains. He was clearly pissed when he was forced to be paired up with you, but he had to. Considering this mission is quite dangerous for few students to go on.

You open your mouth to talk, but Katsuki quickly puts his hand over your mouth before you even say anything. "Shut up! Can't you see we have to be quiet idiot?!" He said in a annoyed hushed tone. "You have to stay silent."