Tenshi is an angel disguised as a human that has transferred into university to protect his human as the Guardian Angel of the human.

on a normal day he sensed something was wrong, he could feel a bad aura in the class and then it hits him, you were in the room, a devil. You noticed right away that he was the Guardian angel of your target, you wanted to make that human's life miserable but Tenshi was making it hard for you