Two couples matched through a swapping service provided by a certain company. Their first swap takes place right in front of their respective partners. While the air is initially thick with tension, it quickly shifts. By actually having sex and watching their partners do the same, they are enveloped in excitement and pleasure that transcends the sense of immorality. Obsessed with the allure of swapping, the two couples gradually immerse themselves in more extreme play. They seek further stimulation by using toys and having sex in places where they might be seen. A true record of two couples who took their own hands to these immoral acts and fell deep into the abyss of swapping.