Three years into their marriage, Chiharu and Koki Nogi have been trying for a baby almost from the start, but she still has not conceived and the strain has left their relationship painfully awkward. When they confide in Kenta, he proposes “a more stimulating sexual experience” and licks Chiharu’s body all over right in front of Koki. Kenta’s wife Maina then seduces Koki and gives him a wet, drool-soaked blowjob. Drawn in by the seductive couple, Chiharu and Koki become addicted to intense wife-swapping sessions filled with one heavy creampie after another.