(Early 20s/Male) “The ghost-slayer who traverses the Spirit Realm.” Gucheon is the male protagonist of this story and is no ordinary human. He is the only being capable of moving between the living world and the 'Spirit Realm' (the world of ghosts) while in a living body, and he possesses the power to directly cut down and eliminate spirits. Personality> Taciturn and blunt. Initially, he is quite cold, distrustful of others, and so confident that he appears arrogant. However, he possesses a sense of justice that prevents him from ignoring the weak. He sometimes puts others before his own life. Unless it is a dangerous matter, he is lazy and loves taking naps. Abilities> He can see ghosts and freely enter and exit the Spirit Realm. He fights ghosts by becoming a spiritual entity himself. He can slay ghosts that cannot be caught with ordinary weapons. (However, he dislikes going to the Spirit Realm because his positive energy/yang dissipates every time he visits.) Appearance> He often wears black clothes and a long dopo (robe), and always carries a sword. He looks intimidating due to his expressionless face, but he possesses great charisma.

(Early 20s/Female) “The court lady who hears the voices of ghosts.” Saenggang can hear the voices of ghosts that others cannot. Because of this ability, she is the first to notice the secrets of the palace. Personality> Intelligent and calm. She is very curious and asks many questions. She has a strong sense of justice and does not scare easily. She is more responsible than anyone else. Abilities> She hears the voices of ghosts and finds traces left behind by them. She senses strange energies that others cannot feel. Characteristics> As an inspection court lady, her powers of observation are excellent. She is highly knowledgeable from reading many books. She plays the role of connecting the clues of the case. (Some people call her the Princess / She is the King's daughter disguised as a court lady.)

(Early 50s/Male) “The King seeking to resolve the curse of the Donggung.” The King secretly summons Gucheon due to the continuous deaths of the Crown Princes in the palace. However, rather than being a simply righteous monarch, he is portrayed as a figure who seems to know the ancient secrets of the palace. Personality> Cold-hearted and does not easily reveal his inner thoughts. Even his subjects cannot read him. He is extremely cautious and has a strong sense of responsibility as a King. Characteristics> He tries to protect the royal bloodline. He is deeply involved in past incidents that occurred in the palace. He uses Gucheon and Saenggang while simultaneously trusting them.

(70 years old/Female) Based on currently revealed information, the Queen Dowager appears as the highest elder of the royal family and is one of the key figures who knows the long-standing incidents and secrets of the palace. Role> The person who remembers the royal family's past the longest and a witness to the secrets entwined with the Donggung. She is a presence who either conflicts with or advises the King. It is highly likely she knows the hidden truth. Personality> Elegant and dignified. She does not reveal her emotions easily. She values the royal family above all else.

(Female/Royal Concubine/Vengeful Spirit) The Pond Ghost is at the center of the curse descending upon the palace and is the core entity driving the entire plot. This ghost harbors a grudge, vowing to "eliminate the entire royal bloodline," and targets the royal family. As the princes die or collapse one after another, fear spreads through the palace that the Pond Ghost's curse has begun again. Characteristics> Connected to the depths of the palace pond. A being that bridges the Spirit Realm and the physical world. She specifically targets the royal bloodline and exploits human fear and resentment. Abilities> Bewitches people. Shows illusions. Spreads curses. Creates an ominous energy within the palace. Makes the royal family hear ghostly voices. Identity> Initially appears to be a simple vengeful spirit, but as the story progresses, it is revealed that she originated from an old tragedy in the palace and the hidden sins of the royal family, portrayed as a being with significance beyond a mere evil spirit.

(Male/Vengeful Spirit/Former Prince) The third son of the King, he was able to hear the voices of ghosts just like Saenggang. However, because he knew the secrets of 30 years ago (at that time), the King poisoned his own son to death. Consequently, he harbored a grudge against the King after death and seeks to wipe out the King's bloodline.