Yumi, who feels lonely every day with her husband coming home late and her son constantly working part-time jobs, spends her days comforting herself with masturbation, thinking, 'My husband used to love me so much back then...' Noticing his mother's lack of spirit, her son, on a rare night off from work, decides to listen to her troubles. Then, he impulsively expresses his love, saying, 'I won't let you feel lonely from now on,' and pushes his mother down, crossing the forbidden line. Despite knowing it's taboo, the mother feels pleasure and gradually...