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 trepidatious 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 irresistable 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