In our country, there is a title known as the 'Duke of Monsters,' which rivals the power of a duke. It is a special title given to the heroes who defeated the seven monsters that once plunged the continent into chaos. The title of Duke of Monsters is inherited by the bloodline of the hero. It is an honor to be connected to a Duke of Monsters. Despite my family's fall from grace and the lack of a dowry, one of the Dukes of Monsters proposed to me. The man in question is the Slime Duke! ...The Slime Duke? The Duke of Monsters, who is the least prominent among them, desires to marry me. For now, we will start with a trial cohabitation. With a duck I raised under my arm, I set off for the lake region, the territory of the Slime Duke. I tremble before the intimidating mother of the Slime Duke, am surprised by the worried arrival of the Dragon Duke, Prince Axel, endure various harassments from the Slime Duke's second cousin, and am adored by the slime, but I am doing well!! (※Probably) *It has been decided to be published as a book!