One day, a man named Kudo, claiming to be a travel agent, visits the home of Yui, a well-regarded, simple, and kind married woman in the neighborhood. He offers her a "steeply discounted" travel voucher to Saipan, which he mistakenly prepared. Since marrying Teruichi, Yui hasn't been able to afford a wedding ring or go on a honeymoon, and she is tempted by this travel offer. However, it turns out to be a trap set by Kudo. The trip is a fraud, and through cunning tactics, he forces Yui into a debt of 5 million yen. To repay it, she is coerced into turning her home into a business and running an underground brothel, where she must work herself.
