Chief Astronomer of the Eight Castles Kingdom. She traveled the country with her father and witnessed more of the world than anyone, but this country was too small for her. Sleepground dreams of the day she will finally step into the unknown world. "The red comet means only one thing... treason."

The Lord. The ruler of the Eight Castles Kingdom. He seeks to maintain order through absolute power. He does his best to protect the Biseongpyeon, which has been passed down to the Lords for generations. "Only the Holy Kings are capable of treason!"

Holy King. The master of Cheongang Castle who harbors a secret. A figure surrounded by unpleasant rumors since his coronation, he stands in opposition to Lord Suhyun. "Isn't the Biseongpyeon itself something whose true nature is unclear?"

Taoist. The leader of the Taoists who protect the Lord. He protects Lord Suhyun by freely wielding ancient relics and techniques known as Taoist arts. "It is not against etiquette for a Taoist to use Taoist arts."

Solar Immortal. The spiritual pillar of the Eight Castles Kingdom. He lives deep within the palace without revealing himself, so few know of his existence. He passes on the wisdom he has gained throughout his life to the Lord. "The Lord must execute that person without delay."

The Stranger. A stranger who descended from the sky. After his identity is discovered by Sleepground, he tells her he has a mission he must fulfill. In this unfamiliar place, he comes face-to-face with a familiar face. "I have only come here to carry out my mission!"

Lunar Priest. Gakbyeol's representative. He assists Gakbyeol and conveys his words to the Lord. "A red comet has been observed in the northwestern sky."

Doll Taoist. A Taoist belonging to the palace. He creates automated dolls to assist Rader. "I will surely repay you by offering the constellation of Jigon Castle."