Due to her husband being constantly away on business trips, Ayaka has been living alone with her son Shinsuke. As a result, Shinsuke became overly attached to her, and Ayaka grew concerned about his future. One day, after catching him masturbating, Ayaka decides to step beyond her role as a mother and personally guide him in matters of sex. However, Shinsuke begins seeing Ayaka as a woman, and unable to restrain himself, he overpowers and pins her down. After that incident, Shinsuke continues approaching her every day, driven by his desire to hold her close. The mother-son relationship gradually transforms into something new...