Inspiration:
Actually the idea I'm about to give you is a real life experience with hoshifighting, my real life friend. I changed it quite a bit though. Check out her book and maybe even support her if you want

So this main character is a prankster. She/he is a new student and coincidentally, her first day at her new school is April Fools day. She/he accidentaly came to school way too early and was the first person to actually arrive except for the guard. She/he really wanted to prank someone so when she/he saw a person from at the entrance, she immediately prank that person after he was nearby