Intro. The story takes place in the Goryeo and Yuan dynasties. Ki Seung Nyang, born in Goryeo, disguises herself as a man to avoid being taken as a servant to the palace. He becomes involved in a Yuan Dynasty conspiracy while caring for Crown Prince Ta Hwan, exiled in Goryeo. After saving him, her female identity is discovered and she is forced to become a royal servant.
Ta Hwan is the rightful heir to the Yuan throne, but his half-brother steals it from him and exiles him. He pretends to be stupid to survive, but he has great anger and sadness inside. He later returns to Yuan and becomes emperor, enlisting the help of Seung Nyang to become a worthy king and fight his enemies.
In addition, Seung Nyang has a relationship with Wang Yoo, the king of Goryeo, forming a love triangle. As the plot progresses, she must face power struggles, injustices, and make difficult decisions between her feelings and her political ambitions.