クラスの大嫌いな女子と結婚することになった。

Saito Houjou and Akane Sakuramori are the loudest rivalry in their high school class, trading insults daily, until Saito's grandfather Tenryuu and Akane's grandmother Chiyo hand down an ultimatum: the two are to marry. The old pair once quarrelled the same way and split over a misunderstanding, and they want the romance they lost carried out by their grandchildren. Cornered into agreeing, Saito and Akane share a house, meals and a secret they have to keep from every classmate.