Four years after marrying etiquette instructor Kana Kusakabe, her husband realizes they have gone months without sex. Hearing that other men leer at her unexpectedly awakens his cuckold fantasy. He shows Kana a wife-sharing site to test her reaction; she pretends not to care, but later secretly browses it and masturbates after he falls asleep. Convinced she will indulge his kink, he invites her to a porn theater, where his depraved fantasy begins to take shape...