Yeon Lokheun is a girl who grows up living as a boy learning martial and spiritual arts. She heads for the palace in order to clear the name of her father, a wanted criminal, where she meets the young Emperor Garyun. He promises to save her father's life in exchange for her lifelong services. After gaining Garyun's trust, she travels the world solving supernatural-like problems that arise in place of the Emperor. But how long can she continue this life without the others finding out that she is actually a woman?