Three years into their marriage, husband Akio and wife Ruri find their intimate life lacking, as Akio's half-hearted penetration leaves Ruri unsatisfied and burdened with constant anxiety and sadness. One day, after Akio picks up a massage flyer while out at the station, he suggests Ruri try it. The masseur, Suetou, possesses a unique skill with his fingers and vibrator techniques, capable of bringing wives to climax repeatedly. Unaware of what lies ahead, Akio decides to invite Suetou to their home. And finally, the day arrives—penetration sex with the husband's cock takes place.