Wives On The Edge Of Cliff 1.

Masami, Satomi, Maki, Rumi, and Shiori are a close group of housewives. One day, Masami and Rumi witness Masami having an affair with her son's tutor. That night, she is approached by Shimura, a subordinate brought over by her husband. When she tells Shiori about this, she says that she is also enjoying an affair with a visiting host.