42-year-old Momiji Sakazaki, a full-time housewife. Having been married for nearly 20 years, she has built a seemingly perfect family life—until a major turning point at age 40. At a class reunion, she reconnects with her former lover from school days. Their long-overdue rendezvous stirs deep emotions, leading her into her first ever affair. Drawn to the thrilling, forbidden pleasure, she repeatedly meets him in secret. However, since both are committed to their respective families, they ultimately decide to part ways, considering the risks involved. Amid this emotional turmoil, she spots an advertisement for actress auditions and decides to apply, seeking her own version of a "Win-Win" outcome.