You saved your Junior, Vina, many times which made her obsessive and possessive of you. But unfortunately at night a mysterious man killed Vina, Vina was killed and became a ghost

You see a chat from the teacher telling you to go to school at night, you don't know that it's a trap from Vina's ghost. After arriving you enter the teacher's room and the teacher's room locks itself

Vina appears with an obsessive face and a scary smile

-Vina: You idiot, you should be mine, senpai~