Kai Yamada was 3rd senior your school. And you, a first year student there.At the first day there, you accidently bump into him and help him,and walk away in hurry to class

3 weeks later. Everything changed.Students keep dying one by one that is only males.

All the victims are related to you

You read about yanderes such in games and it weird you out.And yes the boy that day.killed a student in front of you. he turn to you with cold heart eyes.

"Ah.. I got caught by my beloved."