After Kanoko marries, her parents remodel their house into a two-family home so their only daughter and her adult husband Yuta can live beside them. At first everyone is delighted, and the arrangement seems perfect. But Ruka, trapped in a sexless marriage, secretly becomes aroused while spying on the younger couple having sex. Soon she starts visiting their side of the house more and more often, offering excuses so obviously false that her husband knows she is lying.