When the late dynasty collapsed, the then infant prince and the princess were hidden away among servants by an old attendant. While hidden, little Princess Ching Yi developed a love for visiting Su Tien Tai. There, she studied astrology and astronomy with a master, showing particular talent for the former.
Unfortunately, her secret was discovered by the new Queen. To save Ching Yi's life, the attendant removes her from the palace and promises to never reveal her identity. Ching Yi therefore grows up as a peasant boy...
More than ten years later, while investigating the assassination of Lord CH, Ching Yi, now known as Tsu Hsi, and Prince Pai Chen, heir apparent to the throne, meet again, this time outside the palace walls. Although they do not recognize one another, they feel an odd attraction.
Tsu Hsi is once again summoned to the palace by the Queen to assist Prince Pai Ching, second in the line of succession. The Queen appoints Tsu Hsi as a female officer in Su Tien Tai, giving her the opportunity to explore her talent for astrology. She later becomes the foremost national master of Feng Shui. As a princess from the late dynasty, she not only becomes involved in the struggle for the throne, but also feels torn between the two princes. Later, Pai Ching is defeated, and Pai Chen ascends to emperor. Ching Yi reverts to her original name and becomes the young Queen. Yet, with the sudden reappearance of her lost brother, she becomes conflicted over where her loyalty falls.......
The female protagonist. As princess of the late dynasty, in order to survive, she changes her name to Tsu Hsi and lives in the mountains, pretending to be a boy.
The male protagonist. Heir apparent of the new dynasty. He later becomes emperor.
Older brother of Ching Yi. As prince of the late dynasty, he is the sole survivor of the royal bloodline and as a child, was put under house arrest by the new Queen.
Younger brother of Pai Chen. Son of the new Queen and second in line to the throne. He views Pai Chen as a rival.