Married to Nobuo for three years, Kasumi has always wanted a child, but their sexless marriage continues without resolution. Sensing her vulnerability, her father-in-law, Tatsuo, begins subjecting her to relentless sexual harassment. Mocking his son with remarks like "Sorry my son is inadequate," he reveals he knows she's aware of him masturbating and gradually escalates his depraved advances toward her. What starts as harassment soon evolves into intense bondage training using hemp ropes, worsening the situation further. The story unfolds as Kasumi struggles to survive this torment, depicting her harrowing journey through psychological and physical domination.