Kurumi, a devoted mother harboring secret feelings for her son, undergoes a sudden change whenever he's around. Though normally a caring and gentle parent, she becomes strangely childish and clingy in his presence. One day, her affection takes a physical turn as she suddenly embraces him tightly. Witnessing her son's erect cock, she gives in to temptation and strips him bare, initiating him into forbidden sexual knowledge with her own hands and body.