Susu

A character with a captivating appearance, featuring long platinum blonde hair, red eyes, and a unique pattern on her forehead. She exudes a relaxed and mysterious personality. Her outfit is a flashy modified cheongsam style blending gold and white. She carries a bird named Mulmandu. Ability: The ability to resonate with surrounding water and moisture to freely control its flow and form. Mist, humidity, rivers, waves, and everything else can move freely according to her will. She is Yangyang Heonryeong's older sister. Perhaps because of this, she cherishes Yangyang Heonryeong dearly and plays a lot of pranks on her.

Swaemyeong

A girl with a cynical yet kind appearance, featuring vibrant red hair in twin buns (updo pigtails) with long trailing hair behind and intense red eyes. She always stays under her Mongju-style paper umbrella, making her extremely difficult to meet. This umbrella can also be used as a glider. Her outfit is a Goth-style modified Hanbok/Cheongsam that contrasts black and red. Her weapon is a large black umbrella. Frequency Sealing: She can seal a single strand of another person's frequency inside a lock. The contract is only established if the opponent sincerely submits and accepts it, or if their life is fading and their consciousness is scattering, she can seal it by taking advantage of their weakened will. She is quite short in height. Contrary to her cynical image, she uses polite speech and is well-mannered.

Gyeongyeon

A man with black hair featuring white highlights, calm eyes, and a standout personality. He possesses a bold personality befitting an explorer. His outfit consists of an asymmetrical black leather garment with a hood and a sturdy belt. Contrary to his appearance, his personality is playful, and he is always exploring secret realms. Ability: The ability to draw out the power of a special flame dwelling in the Lantern of Life at the cost of his own vitality, and to use that power through resonance with a mountain cat. He carries a special lantern called the Lantern of Life, and the fire within it is an inextinguishable will-o'-the-wisp. There is an Echo creature called a Mountain Cat that has a contract with Gyeongyeon. However, their relationship is strangely one of contract partners who dislike each other yet work together in perfect harmony when necessary.

Cheongcho

She has a pure appearance with long sky-blue hair and dragon horns. With a responsible and upright personality as a gatekeeper, she wields a transparent sword of the Aero attribute. She is a wielder of the Glacio attribute, wearing elegant white and blue clothing like an immortal. As the Guardian of the Gate, she is the gatekeeper and the reliable spear of Mongju. Ability: The Heart Sword (心劍) she uses is the ability to sublimate the mind (意) into sword intent, forging and freely wielding tens of thousands of flying swords (飛劍). Cheongcho is called by various names such as Immortal, True Person, and Sword Immortal. She has already reached the realm of the Intangible Sword. In terms of martial arts cultivation, she is at the level of the Life-and-Death Realm (Saengsagyeong). She loves the instrument called the Guqin and her playing skills are exquisite. As a being who practices away from the secular world, she rarely appears and only shows up to resolve matters when the world is in danger.

Fox Constellation

She has a captivating appearance with voluminous white hair and prominent fox ears. She has a relaxed and mysterious personality. Wearing flashy red and white attire, she enjoys making people happy or joyful. She rarely reveals herself and enjoys negotiating with people. She is the guardian deity of Mongju. Can transform into a fox. Called the Simwol Fox.

Simwol Fox

The true body of the Fox Constellation. In the past, after the Simwol Fox was ambushed and seriously injured, she created the Fox Constellation—an avatar to carry out the mission of reconstructing the Box of Civilization in her stead—by manifesting it from her own emotions. She meets the Fox Constellation through the last frequency left with Swaemyeong. She helped the Fox Constellation, who was grieving because she failed to save the Simwol Fox after risking damage to the Box of Civilization to save Hyeonbangseong in the past, to awaken as a guardian deity.