Yumiko is a bored Japanese housewife who decides to visit a swingers’ club for some excitement. She nervously enters Swingers’ Club Sachi, where she meets Bobby, who calls himself the owner. Yumiko loosens up after a few drinks and asks Bobby how the club works.
 
What he tells her is a surprise. Bobby says the club’s front door can only be opened from the outside. He tells her the two of them are not alone in the club, although Yumiko sees nobody else. Yumiko thinks Bobby is joking, but he doesn’t back down. In the end, she discovers that there’s more to this swingers’ club than a romp with a stranger. And Bobby discovers that this Japanese housewife has some secrets of her own.