There is nothing special about Takashi Komiya, except for his incredibly hot Russian step-mother and step-sisters. The Komiya family is now filled with voluptuous and erotic women: Yuriya, his lustful step-mother with a gravure modeling past, Anna, his diligent but repressed older sister and Rina, his bratty but secretly masochistic younger sister. Takashi resorts to blackmail after he discovers their secret lives filled with naughty cosplay and late night sex with strangers. Now he is determined to strengthen the family bonds by satisfying all the slutty women living in his house, even after Dad comes back home.