Taro accidentally witnesses his mother, Mirai, masturbating in the middle of the night, six years after her divorce. Realizing that his always-smiling and hardworking mother is actually a woman harboring sexual frustration, Taro wants to help her. He consults his friend Shota, a smooth talker and womanizer, and pleads with him, "Just once, please sleep with my mother." Surprisingly, Shota readily agrees and arranges for dinner at Taro's house. Taro deliberately goes out shopping, leaving Shota and Mirai alone. Shota approaches Mirai, giving her a passionate kiss and oral sex before leading her to the bedroom. Initially hesitant, Mirai is gradually seduced by Shota's skillful techniques and becomes increasingly aroused...