Thirteen years after marrying and leaving her job as a teacher to focus on family life, Ayumi appeared to be living a smooth, successful life. However, beneath the surface, hidden desires began to stir within her—desires she never revealed to her husband. At a long-awaited class reunion, she reunited with Shuuto, her former student, and the two quickly became involved in an affair. Her body, now past forty, was awakened and stimulated by the passionate energy of a younger man, driving her to seek new pleasures. Without her husband noticing, Ayumi had already fallen for another man. When the secret finally came to light, her husband summoned a colleague and made a firm decision—.