The president's daughter, Yoon Jae-hee (Jun Do-yeon) is a Korean diplomat in Prague. She has only recently recovered from a devastating break up five years earlier with Ji Young-woo (Kim Min-joon), the son of a prominent Korean businessman. Choi Sang-hyun (Kim Joo-hyuk) is a detective who goes to Prague searching for his ex-girlfriend Hye-joo (Yoon Se-ah). Hye-joo broke up with Sang-hyun over the phone from Prague and Sang-hyun can not accept it. Sang-hyun meets Jae-hee in Prague and misunderstandings abound. Eventually the two help each other and become friends. When they return to Korea love blossoms, but their respective ex's and very different social status put it to the test.