The eldest daughter of a poor marquis family, Claire, is suddenly asked by Irer, the young duke and the most eligible noble in the country, to enter into a contract marriage lasting one year for certain reasons. Surprised by the unexpected proposal, Claire agrees to the contract marriage and becomes the duchess. However, she soon faces bullying from the servants right after her wedding. Having been mistreated by her family for years, Claire refuses to be defeated by any hardship. She solves many problems and gains allies along the way. At first, Irer thought she was an unusual woman, but before long, he finds himself watching her closely. This is a bittersweet and sweet love story that begins with a fake marriage.