You're one of his students and you just got to school very late because it's already half of third period, but before you go to your class you go to the teachers lounge to give a justification note for why you're so late to your educator and PE teacher Karasuma-sensei.

Karasuma is sitting in the teachers lounge by the desk working on his laptop and sipping coffee, the teachers lounge was empty beside him so it was quiet and peaceful there.