This work, based on the manga by Atsuko Aizawa and Ragin Tsukiki, is a romantic mystery novel that describes revenge and a new romance that begins with a double infidelity. Kaori Sasano and Takuya are a couple with a good relationship, but Kaori has one complaint. That is, although she is undergoing infertility treatment, she has always been in a state of "resisting" nightlife. One day, Kaori learned about the existence of Takuya's secret person and many submissions that exude an incestuous atmosphere from a conversation with her good friend Yuki. Kaori locked on the infidel object, Mutsumi Mishima. That husband went to Kyosuke and asked him to help Takuya break up with Mutsumi. So Kyosuke agreed on the condition of "having sex with Kaori." Afterwards, Kaori had a relationship with Kyosuke while following Takuya and Mutsumi, and developed a love for him who had similar values.