Yuko is a married woman who lives with her son, a university student, while her husband is away on a long-term assignment. Although she was happy, she may have been feeling lonely from not being able to meet her husband, or maybe somewhere in her heart she was looking for stimulation. One day, her son's friend comes to pick up something she forgot, and she is attacked and forced into a relationship with him. From that day on, her daily life was gone. Her son's friend's demands escalate further.