After ten years of marriage, he still loves Ririko but has developed a cuckold fetish that makes it difficult for him to touch her himself. Desperate to watch his wife with another man, he finds a private members-only swingers club where husbands let strangers have sex with their wives. Membership requires bringing a partner, so he persuades Ririko to enter on the promise that they will only watch—but the night begins to move far beyond that promise.