Elvir is a princess born to the king of the volcanic country of Fastu and her mother, a wildcat beastman. As a special exception to her status as a princess despite being a bastard, Elvir was married to King Arnold II of Zugvogel, a major power in the world. However, he is known as the "cursed king". To make his marriage proposal, his half-sister Ruby, who has been harassing him for years, comes along as his lady-in-waiting!