After her husband loses his job and accumulates massive debt, married woman Erina is forced to move into her in-laws' home. While helping with household duties, she lives in constant fear of her domineering father-in-law, Kofu. His predatory advances grow increasingly aggressive, subjecting her to degrading and humiliating demands. As Erina is gradually forced into the role of her father-in-law's sex slave, the story unfolds with intense drama, depicting her suffering and inner struggle.