To pay for her husband's embezzlement of company funds, Rui is entered into the "Chikkou GP," an anal exhibition where anal enthusiasts gather. Locked in a cold, dark cell, she is subjected to anal inspections by multiple analysts who smell her ass and use magnifying glasses to count every wrinkle. To become the No. 1 anal, Rui is trained nightly. Though she endures these humiliating days for her husband's sake, her body gradually begins to feel pleasure through her ass, and her talent as an anal slave begins to bloom...
