In the midst of a desperate war, the King clung to the power of a demon. To win the war, he entered into a contract with a fearsome demon, and the compensation demanded was... a "Family"!? After the war, to meet the demon's demands, Saintesses and Knights were offered by the country as the "Demon's Family." They attempt to take advantage of any opening to defeat the demon, but his power is immense. Furthermore, he envelops his family with deep love——...!? A new romantic fantasy drawn by Nakami Nowaki of "Royal Tailor"!