Harumi (Harumi Nishimoto), married to a laundromat owner, lives a seemingly happy life with her kind husband, Tomomi, and his mother, Kiyoko. However, her one deep frustration is Tomomi's impotence. For the once-promiscuous Harumi, this becomes unbearable, and she frequently resorts to masturbation to relieve her desires. One day, her former lover and playmate from her wild past, Ishino, visits the shop. Though hesitant at first, Harumi eventually finds herself stepping into Ishino's home, tempted by his advances. Meanwhile, Tomomi, seeking advice from his mother, is urged to try a potent aphrodisiac imported from South America. As both husband and wife pursue separate paths to rekindle their sex life, their choices threaten to unravel the fragile balance of their marriage.