Hikari and Ryuta live with their mother. Ryuta's friends also complain, "I wish my mother was as beautiful as her." Ryuta also strongly considers Hikari as a woman. One day, Ryuta is caught by his mother masturbating with his mother's underwear. After that, he tells his mother that he likes her for a month, not caring about what happens. Showing affection, Hikari also begins to like Ryuta as a member of the opposite sex, and they greedily seek each other...