Yukine Kuramoto spends her days in loneliness after her husband is transferred for work and her son moves out. Tired of her monotonous routine, she begins working as a cleaner at an office, where she meets Toyo, a young employee at the company. Toyo becomes instantly infatuated when he catches a glimpse of Yukine changing in the locker room, stunned by the striking contrast between her plain, innocent demeanor and her glamorous, voluptuous figure. Gradually, the two grow closer through small, unexpected moments. The film captures Yukine's descent into secret passion as she's drawn to the thrill of their illicit encounters and overwhelmed by Toyo's youthful, vigorous body. A quiet yet transformative romance unfolds, bringing unexpected excitement into her otherwise ordinary life.