Kanojo ga Koushaku-tei ni Itta Riyuu  

Why Raeliana Ended up at the Duke's Mansion, Geunyeoga Gongjagjeolo Gaya Haessdeon Sajeong, 그녀가 공작저로 가야 했던 사정, 彼女が公爵邸に行った理由, พระเอกของฉันเป็นท่านดยุค, Como Raeliana Foi Parar na Mansão do Duque, Comment Raeliana a survécu au manoir Wynknight

In contemporary Korea, Park Eunha passes away and then finds herself reborn as Raeliana McMillan, the eldest daughter of a wealthy baron. However, this world is identical to one she had read about in a novel. Despite being cherished by her family, Raeliana feels like she's living in a fairy tale. But unlike the main character, Raeliana isn't the central figure; instead, she's just a plot device whose murder at the hands of her fiancé sets off the entire story. Raeliana is determined not to accept her fate passively. She decides to target someone in power - Duke Noah Volstaire Wynknight, the wealthy male protagonist of the novel. Using her knowledge of future events, Raeliana offers information to Noah on one condition: he must pretend to be her fiancé. However, Noah's duplicitous nature complicates things for Raeliana.