Aki and her husband divorced, and the son decided to live with his father. The day before they left home, Aki had an affair with her son Naoya because she was so lonely. From then on, the only day she could meet Naoya once a year was Aki's reason for living. Eventually, Naoya's father remarried, and Aki was worried that Naoya would be taken away by her mother-in-law. Since her mother-in-law was born to Naoya, the day has come for her to meet for the first time...
