Ten years after divorcing her husband, Sayuri raised her son Daigo as a single mother, living naturally and freely in their home. She often walked around in lingerie or braless in front of Daigo, and accidental upskirt views were an everyday occurrence. One day, while cleaning Daigo's room, she discovered an adult video. Overcome with excitement, she masturbated and fell asleep. Her body, untouched by a man for years, writhed lewdly in her dreams. Feeling compassion for Daigo, Sayuri resolved to initiate him with maternal love.