Drama depicts the delicate relationship between female university student Hong Seol (Kim Go-Eun) and her senior Yoo Jung (Park Hae-Jin). Hong-Seol works part-time due to her family's poor background. Yoo Jung is good looking, gets good grades, athletic and has a kind personality, but he has a dark side.

At the Sky House, she meets Kang Ji-woon (Jung Il-woo), a soft hearted but lonely and wild-child rebel, Kang Hyun-min (Ahn Jae-hyun), a playboy plutocrat who does whatever he wants, Kang Seo-woo (Lee Jung-shin), a top singer-songwriter who is gentle and kind to Ha-won, and finally Lee Yoon-sung (Choi Min), the Chairman's secretary and their bodyguard.