Kana Momonoki's brother is in debt, so she is kidnapped and held captive by an insatiable yakuza who demands her body as repayment. For ten days, she becomes his woman, forced to obey his every command. Whenever he wants sex, she must immediately present her ass for penetration. Drowning in waves of pleasure, she spends her days drenched in cum. Her lustful body grows increasingly aroused, unable to calm down. Each time he thrusts into her, she reveals an even more lewd and depraved side. Her body gradually transforms, molded entirely to satisfy his desires.