A young girl is raised as a killer in the Yanbian province of China. She hides her identity and travels to South Korea where she hopes to lead a quiet life but becomes involved with two mysterious men.

Jang Yoon-Ha is the youngest daughter of a chaebol. Even though her family is extremely wealthy, she holds a part-time job at a food market. She hides her background as an heiress and attempts to find a man that loves her for herself.

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?