She meets her alluring, mature woman friend, a woman whose identity they both know, at a box-shaped massage parlor, and they have an affair. (Hojo Maki DASS-907)

Ryosuke harbors a secret longing for his wife's mother, Yuma. One day, after arguing with his wife, Ryosuke goes to a massage parlor as revenge. There, he encounters Yuma, who works as a waitress. After a struggle, he lets Yuma ejaculate for him. Ryosuke is overwhelmed by an unprecedented pleasure. Yuma, who hasn't had sex with her husband at night, gradually opens up to Ryosuke.