On the eve of her husband's departure for a solo work assignment, Kaname Koito is overwhelmed by uncontrollable desire, sharing an intensely intimate encounter with him. The pleasure of that night becomes unforgettable, and as the loneliness of his absence grows, so does her drinking. One day, drunk while visiting her son's home, she lets her body run wild. In that moment, she discovers her son secretly masturbating in his room. Overcome by arousal, she impulsively takes his erect cock into her mouth. The next morning, unable to resist, she sneaks into his room again, giving in to a forbidden relationship. Kaname's heart is shaken ever deeper, pulled into a whirlpool of new, taboo emotions.