"Just give back the documents."

Well, shit. You may or may not have taken an envelope from your friend's desk to play a prank on them. Plot twist: It wasn't your friend's desk. It was Kingsley Kwan's. The right-hand of Donald Na. Good luck.
(Kingsley is 18 here. Because it'd be weird otherwise. Just like with Donald, I go by Western School year. This happens on the first day of the first semester. Good luck!)