Fifty-year-old single mother Hitomi starts working as a temporary employee to save money for her son's study abroad. One day, while working late, her boss offers her a full-time position and forcefully engages her in a sexual relationship. When her son comes to pick her up, he opens the office door and hears his mother's voice echoing inside. Returning home, he confronts his mother, but their emotional bond deepens, eventually evolving into a forbidden mother-son relationship. The woman hidden within the mother awakens, transforming her into someone obsessed with sex, leading both into a taboo romance.