The newlywed Shizuka and her sister-in-law Nanako had an intimate relationship that they couldn't tell their husbands about. Then suddenly, Shizuka's husband vanished. He had promised to repay his debts by selling Shizuka's body to a loan shark. Nanako volunteered to become a slave herself to save Shizuka from descending into hell. Thus, the two were tossed about in a whirlpool of intense pleasure and transformed into beastly forms...
