After losing her husband, Nobuko found herself alone, with no one to turn to but her own hands for pleasure. Yet her growing desire soon began to cast a seductive spell over her son-in-law, who lived with her. One night, he accidentally witnessed Nobuko masturbating and lost all self-control. Overcome with lust, he pursued her in a forbidden relationship. Torn between guilt toward her daughter and her own primal urges, Nobuko wavered. Her decision would change their lives forever.