Couples engage in sex swapping, leaving husbands jealous as they watch their wives being embraced and panting by other men. (NGOD-227)

The Hatano couple has a problem: the husband, Abe, can't get an erection during sex and hasn't had sex for over a year… Yui is also troubled by her inability to achieve satisfaction. The Kuroki couple, who live next door in the same apartment building, are very sexually active and don't shy away from making love openly; they are a very passionate couple. One day, as Yui walks down the shared corridor, she peeks through a crack in the door and sees the Kuroki couple having sex…