In the house next door to Kohei, there lives a beautiful wife, Yuri, who is the talk of the neighborhood, and her husband. Yuri and Kohei first met when Yuri came to his room to retrieve a pair of panties that had been thrown in. Yuri is overwhelmed by her wild lewdness, with no panties and a toy between her legs, and the two of them have sex. Kohei finds out that the panties are an invitation from the couple next door, because he has peeked at the whole perverted play that takes place every day, and that Kohei has been invited to join in on the fun...