Baek Cheon and Ye Hwa, born at the same time and day, grew up together like sisters. However, both lead contrasting lives, with one being the last princess of Kangwi country, and the other being a nursemaid's daughter serving the princess.

As time passed, Baek Cheon, aware of her engagement to the emperor of Daeju, decides to run away with cries for freedom and true love. In the end, Ye Hwa was made to enter the palace in princess Baek Cheon's stead.

Using their indistinguishable looks, the two of them switched places and entered the palace together after many troubles. However, in contrast to the extravagance, the palace is filled with dark secrets, and they are now embroiled in its events.

The dangerous double life of Ye Hwa, who switches back and forth from a maid to a princess, just how will it end...?!