Eriko Miura is a devoted mother living alone with her son, who dreams of becoming a doctor. One day, her son returns home from school feeling dejected. When she asks what's wrong, he confesses that he asked a female classmate to let him practice physical examinations on her body, as part of his medical training, but she rejected him. Witnessing her son's innocent sorrow at being blocked by sexual taboos, Eriko makes a heartfelt decision—to personally provide him with real sex education using her own body. A touching and bittersweet story unfolds, driven by maternal love and a mother's desire to support her son's dreams, blurring the lines between guidance and forbidden desire.