You play as a high school girl, Naomi. You are the daughter of the CEO of an interesting company that makes toys for children. The story begins when your mother receives a letter from your father, who has been away from home for some time. He asks her to come to his new house, which is somewhere in the city.

When you get there, you discover that there are some strange things happening in the house. First, you see five men on the floor. They eventually get up and tell you that they were attacked by some dangerous 'misfits'. They passed out as soon as they entered the house.

You find out that they are incubi, 'demons who consume and use sexual energy of humans to survive'.