"Renjo-kun, I want you to be my fiancé."
Renjo Toru, who helped the most beautiful Nordic girl in school—Aino Luthi—at a bookstore, is suddenly asked by her to become her fiancé.
At first, it was merely a request to avoid a political marriage, but once Aino learned that her partner was Toru, she suddenly became eager about marriage…!?
This is the story of two people who were supposed to be only fake fiancés, but gradually come to understand each other and eventually become true lovers.