Yuu and Sumi are housewives living next door to each other in the same apartment building, regularly visiting one another and sharing a close friendship. One day, a suspicious investment scam salesman visits Sumi's apartment. Yuu rushes over with her husband to help, driving the salesman away. However, this incident triggers a major turning point in Sumi's life. The salesman was actually a yakuza member, who begins plotting revenge, dragging Yuu and her husband into his scheme. Soon, he threatens Yuu's husband and forces him into committing the heinous act of non-consensual creampie intercourse.