Shiho is an elite detective who, alongside her beloved husband, has solved one serial case after another. One day, her husband, who was investigating the massive drug syndicate "Yamakita Union," becomes infected with drugs, his body slowly deteriorating. As he collapses helplessly, Shiho weeps beside him, swearing revenge. She infiltrates the Yamakita Union's hideout disguised as a drug mule. However, the syndicate uses a special method involving the anus to safely transport narcotics. In order to gain the boss's trust, Shiho has no choice but to comply, sacrificing her own body—submitting her anus to their brutal demands.