As her husband becomes less attentive in bed, Iori Ryouko struggles to suppress her growing sexual desires. Sensing her inner turmoil, her brother-in-law takes control of her by force. Though she verbally resists, her primal instincts as a woman awaken with intense longing, causing her to writhe passionately. Gradually, she begins to feel pleasure in being used as an object for her brother-in-law's lust. Soon, her stepson becomes involved as well, heightening her sense of taboo and driving her pleasure to new extremes.