Neighbors Jiro and Ryuji are close friends who drink together during the day, even after retirement. One day, Ryuji, drunk and out of control, forcibly has sex with Jiro's wife, Kyoko. Upon discovering this, Jiro seeks revenge by sexually dominating Ryuji and then sleeping with Ryuji's wife, Aiko. The deep bond between the two neighbors is shattered in an instant due to a single mistake.