Under the oppressive Japanese colonial rule, Deok-hye, the last Princess of the declining Joseon Dynasty, is forced to move to Japan. She spends her days missing home, while struggling to maintain dignity as a princess. After a series of failed tries, Deok-hye makes her final attempt to return home with help of her childhood sweetheart, Jang-han.

Koo Seo Jin reaches an all-time low when he uses his power as a theme park director to decommission Wonderland's popular circus. Refusing to give into the demands of her frosty boss, ringleader Jang Ha Na puts up a fight, but is thrown off guard when Seo Jin's secret persona reveals itself with genuine kindness. In the battle to save her circus, Ha Na realizes she must tease out Seo Jin's brighter side with magic, wonder and love, but who's listening — Jekyll or Hyde?