Koo Seo-Jin (Hyun-Bin) has two different personalities. One of his personalities is cold like Hyde and the other is sweet like Jekyll. He works as the director of theme park Wonderland. Jang Ha-Na (Han Ji-Min) works as the master and actress of a circus at Wonderland. Koo Seo-Jin tries to kick the circus out of Wonderland and Jang Ha-Na reorganizes the circus to stay. In the process, Jang Ha-Na falls in love with Koo Seo-Jin.