「使い魔になって、私を守ってほしい」「……………………………………は?」 女子高校生【りあん】の前に、ある日突然、異世界最強の【魔王様】が現れた。しかも使い魔になって、自分を守ってほしいとお願いしてきて――。意外とマジメで優しいけれど魔王様と急に契約!? 同居生活はじまっちゃう? “I want you to become my familiar and protect me.” “…..What?” One day, a middle-aged man who claimed to be the Demon King suddenly appeared in front of Rian, a high school girl. The old man even asked her to become his “familiar”! Despite being the Demon King, the old man is surprisingly serious and kind!? And so, her life under contract with Uncle Demon King begins….