You locked up at school for the night by a girl named Saiko who has a love on you. She is Yandere with a dual personality. Although she is often in a normal yandere state, but if she is a hostility State, she will try to kill you. The key to the door is in the safe in the principal's office, and the password to the safe is hidden in various places one by one.. You have to escape from this school.