Kosuge, recently married, had vowed to fulfill her duties as a full-time housewife and devoted wife. However, she had been involved with a flashy man even before marriage, and ever since, her married life had become incredibly dull and monotonous. One day, she found herself browsing a secret affair website. Before she knew it, she became obsessed with exchanging messages with a stranger, eventually inviting him over while her husband was away at work, and indulging in an affair. Kosuge is no ordinary woman—she's had over a hundred sexual partners, and has a history of being a mistress and stealing men from other women. Drawing on her vast experience, she throws herself passionately into this new illicit romance.