One day, a man named Kudo, claiming to be a travel agent, visits the home of Yui, a simple and kind married woman who is well-known in the neighborhood, and offers her a "cheap" trip to Saipan that he claims to have prepared by mistake. Since marrying Teruichi, Yui has not been able to buy a wedding ring or go on a honeymoon, so she is drawn to the trip. However, it was a trap set by Kudo... The trip is fake, and he cunningly puts Yui in debt for 5 million yen, and in order to repay the debt, he forces her to use his home as a store and run an illegal sex business where he works...