Reincarnated as a minor character in a novel, Cha Seon-taek unexpectedly spends a night with Prince Kyungsung, sparking an intense and unexpected romance.
University student, K, is an ordinary young woman who one day finds herself in her favorite romance novel set during historical times. She has now become the minor character Cha Sun-Chaek, the daughter of a wealthy noble family, whose dream is to have a peaceful and normal life. Cha Sun-Chaek, while possessed by K, then spends one night with Yi Beon, the novel's lead male character, who comes from a royal lineage and is favored by the King. He is cold-blooded, gifted with an attractive appearance and outstanding martial arts skills. Somehow, Yi Beon and Cha Sun-Chaek happen to meet and talk, and he is consoled by her about his heartbreaking past. They spend the night together. Soon, Cha Sun-Chaek tries to connect Yi Beon to Jo Eun-Ae, who is supposed to be the lead female character in the novel.