A boy, Kamiya Wataru, lives with his father after loses his mother. Suddenly, his father leaves the house for a while on a business trip abroad. His life takes an unexpected turn when a female college student, Hazuki Luna, moves in as a boarding student.

Mikio and his older brother Saneo, who is mentally handicapped, live together and have just buried their father. One day, Mikio hires a hooker named Marin for his brother. Marin is an underground singer who goes by the name Fala. A video producer who is filming Fala's documentary finds out about her double life, and proposes to film her and Saneo's sex life. Dreaming about leaving Tokyo with Saneo with a huge sum of money from the film, Mikio and Marin agree to the offer.