Eun Ha Won (Park So Dam) is a high school student who dreams to be a veterinarian, but needs money for her education. She ends up living in a mansion, Sky House, with three third-generation chaebol cousins under same conditions.

Kang Hyun Min (Ahn Jae Hyun) is a playboy plutocrat who does whatever he wants while Kang Ji Woon (Jung Il Woo) is soft hearted but lonely and wild-child rebel who rises in status to a member of the royal family in the Sky House. The third cousin, Kang Seo Woo (Lee Jung Shin), is a top singer-songwriter who is gentle and kind to Ha Won.