Mana, who grew up in poverty after her father disappeared owing a huge debt, married a company executive and finally began living a happy life. However, while her husband was away on a business trip, she was kidnapped and imprisoned by a servant man consumed by twisted desire. Each time she is tied up, she begins to feel pleasure, gradually descending into the role of a sex slave. As her harsh confinement continues, her mind slowly transforms, leading her down a new, dark path.