Mari Kei

Newly married Kazuo is troubled by the word "Takaraboin" that his wife Chiharu muttered in her sleep. One day, Kazuo learns from his uncle Kenji that "Takaraboin" is a sexual position. When Kazuo finds out that Chiharu had been dating Kenji before they were married, he decides to take revenge together with Kenji's wife.

Goro and Wako have been together since their high school drama club days, and their hobby is to record each other's daily lives on video. However, Wako decides to study abroad to dance in order to fulfill her dream, and breaks up with Goro.