Reiko, a devoted mother with a son about to advance to school in spring, had always doted on him and protected him excessively. But one day, her life changes completely when she learns her son was caught shoplifting. Just as her son's school recommendation had been secured, this scandal erupts. To make matters worse, the teachers present her with an abnormal demand as a condition for settling the matter: "Spend one day serving the male teachers." For the sake of her beloved son, Reiko obediently submits. Yet gradually, she begins to awaken to the masochistic desires buried deep within herself. As her inner turmoil intertwines with her bond with her son and her relationships with the teachers, the story unfolds into unexpected developments.