Lost Paradise in Tokyo (2010)

Original title: ロストパラダイス・イン・トーキョー

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.