"When was the last time I had sex with my husband...?" Chihiro was consulting her friend Miyuki. Seeing Chihiro like this, Miyuki suggested that they all go out together, including their husbands. A few days later... Under clear skies, at the barbecue spot, Miyuki's husband Ryuichi took advantage of Chihiro while Miyuki and Chihiro's husband weren't looking. Sex in a place where it shouldn't happen, with someone it shouldn't be happening with. Chihiro felt something strange happening to her body. Then, a few days later, Chihiro's phone rang...
