After marriage, the Minami couple remained affectionate, making love every night until late. However, due to work-related stress, the husband gradually lost his ability to get an erection, causing their relationship to grow cold. Serina, a sexually passionate wife, began relieving herself through masturbation day and night, yet remained unsatisfied, her inner frustration building. One day, while deeply engaged in self-pleasure, she accidentally made eye contact with her neighbor, Takagi. Rushing over in panic, she became acutely aware that he had seen her—and to her surprise, the humiliation only intensified her arousal.