The Duke's Daughter Windsor lost her parents in a car accident several years ago, and she herself was left blind. Supported by her fiancé and her younger sister—who is not related to her by blood—she somehow managed to get by day to day. However, after secretly undergoing treatment and regaining her sight, Windsor discovers that the two have betrayed her and are plotting to take over the dukedom. Driven into a corner, Windsor sets out to ask the person who treated her eyes for help in ruining the wedding ceremony—but she mistakenly approaches the wrong man. That man is Theodore, the head of Blark Bank, who is currently being pursued by the police after being falsely accused of a crime by none other than Windsor’s fiancé. With their interests aligned, Theodore proposes a contract marriage to Windsor. How will the two of them confront and overcome the hardships ahead…?