Eun Ha Won is a young woman with 10 part-time jobs, trying to earn money to go to college. When she realizes an accounting mistake will sap her of her savings, she agrees to haughty rich boy Kang Hyun Min's ironic request to join him at his chairman grandfather's fifth wedding.

Chairman Kang, in light of Ha Won's behavior at his wedding, offers her a tantalizing deal that could solve all of her problems.

Ha Won agrees to move into Sky House, but is trepid about what will meet her there. Hyun Min decides to carry on his joke of being engaged to Ha Won.

Hyun Min realizes that Ha Won isn't enamored with his money and finds her irresistible because of it. Chairman Kang gives Ha Won her first assignment, get the three Kang Cousins to eat a meal together.

Chairman Kang honors his three dead sons on the same day every year, and Ha Won is tasked with making sure the grandsons attend.

On the day of her graduation, Ha Won realizes that she didn't fulfill her side of the bargain, and leaves Sky House. Having nowhere to go, an unexpected ally appears.

Ha Won's new assignment is to get the boys to go on a trip together. Realizing it is possibly her most difficult task yet, she enlists the aid of some allies to aid in her cause.

The forced retreat is here, and the Kang Cousins come willingly. Well, most of them. Ha Won wants a wholesome time with friends, but Hye Ji has an ulterior motive.

After a night of drunken revery, the Kang Cousins have some regrets. Ha Won injures both her pride and her ankle.

Ha Won uses her injury to her advantage. A potent "love square" emerges. Secretary Lee is put in an awkward situation.

Ha Won is confused by the dynamic of a new house-guest at Sky House. Hyun Min tries desperately to be a good person, but isn't sure he knows how.

Yoo Na pivots to a new target when she realizes Hyun Min isn't paying attention to her. A figure from Ha Won's past emerges, and his goals appear to be less than sincere.

Ji Woon confesses his feelings, which brings up a world of potential trouble at Sky House. Hyun Min confesses feelings of his own. Chairman Kang appears not to have any feelings.

When Chairman Kang collapses, the boys all get tested to see if they can match as potential donors.

Ji Woon intends to get what could be his last chance at a date with Ha Won. Hyun Min takes a stand against those trying to take over Haneul Group.

Ji Woon's surgery commences, and the Haneul Group vote on their future. Seo Woo makes a decision about his career.