Set in the 18th-century Joseon, it tells the story of Crown Prince Lee Sun and his fight against a powerful and wealthy organization Pyunsoo hwe, who controls the country behind the scenes. He becomes a hope for the people who suffer from lack of water due to the greed of Pyunsoo hwe, who tried to privatize the nation's water supply. With the help of the woman he loves, Ga-eun, Lee Sun overcomes adversity and grow as a just ruler.

A part of the Three Color Fantasy trilogy, the drama focuses on a girl, Nan Hee, who believes she is ugly. After falling for a handsome guy, she uses a family ring with the power to appear beautiful to the boy she likes.