During her husband's business trip, Mao and her husband visit their boss, Yamada, who has always been kind and helpful. After enjoying a meal, Mao returns to retrieve a forgotten item when she suddenly finds herself trapped in a nightmare. Yamada forces her to drink a drugged beverage, rendering her unconscious and helpless. Bound and restrained, Mao struggles to resist, but Yamada's threats and relentless acts of forced confinement escalate into violent rape. As his sadistic desires unfold, he systematically breaks her down, training her to submit completely. Gradually, Mao is dominated and transformed into an obedient vessel for his twisted pleasure.