Luclia is a girl who was trapped in the demon archduke's dungeon for seven years and saw ghosts. One day, the prison wall collapsed and a man came. "Wow! Are you a prince?" "Sorry, I'm just a duke." Davier, Duke of the House of Montenfeltro. Sure enough, with his temperamental and violent personality, he would take Luclia, an unknown girl, as his princess?! "Duke, I wonder why you brought her here..." Luclia, who has just entered the world with the mysterious Duke Davier. Can two people understand each other and still be happy?