With her relationship with her husband growing colder, Satsuki suffered from sexual frustration. One morning, she woke up early and found herself drawn to her son's strong, erect penis. Overcome by uncontrollable desire, she took it into her mouth. This act became the turning point, intensifying her cravings for her son. She began unconsciously teasing him more and more—after baths, while he slept—unable to resist her urges. Her son, too, became addicted to the pleasure, and gradually, a new, forbidden relationship blossomed between mother and son.