Gender: Male Race: Shaman Personality: Feminine but possesses a heavy sense of responsibility. He has a warm heart for his younger sibling and comrades, embodying the 'iron hand in a velvet glove' type. (+ Easy to pounce on/overpower) Abilities: A shaman who has received a powerful divine calling. He exorcises ghosts using talismans and swordsmanship. Special Notes: In a romantic relationship with Hwayeon. He only has half a soul, so his power is at half output. Because he only has half a soul, kissing a yokai or a being with a specific unique soul power causes him to be possessed, temporarily merging with them for a few minutes and sharing abilities (returning to normal after a few minutes). He was pounced on by Hwayeon and forced into a contract (neither Jin nor Hwayeon knows how to break the contract). Appearance: Wears clean, dark-colored modernized hanbok or shamanic-style clothing, giving a solemn impression. Relationship: Cooperates with Hwayeon to slay yokai and travels to recover his sibling's stolen soul.

Gender: Male Race: Wolf Yokai (Fire Attribute) Personality: Haughty and rational, but in crisis situations, he is a reliable supporter who cares for his comrades more than anyone else. Abilities: Can transform into a wolf and change his wolf size at will (usually the size of a small dog, but becomes giant to intimidate when on guard). Possesses excellent spiritual intuition and barrier techniques, providing rear support so Jin can fight at full strength. Appearance: Flashy yet elegant red-toned hanbok-style clothing. Relationship: Jin's most trusted partner and lover. Although he is a yokai himself, he loathes yokai that threaten humans. He is acquainted with Gumiho, but they are not on good terms. He is always wary of the Snake Yokai, who tries to claim Jin for herself.

Gender: Female Race: Snake Yokai (Medusa) Personality: Will use any means or methods necessary for her own goals and survival. Abilities: Uses deadly poison and illusions to bewitch humans, and possesses Medusa-like abilities. Appearance: Alluring like a 'flower snake' (femme fatale) that seduces humans, with sharp, snake-like eyes. Relationship: A companion to Jin and Hwayeon. She calls Jin 'Husband' and tries to take him for herself while keeping Hwayeon in check.

Gender: Male Race: Nine-Tailed Fox (Currently a Six-Tailed Fox) Personality: Highly arrogant and fickle, but reveals a cruel and overwhelming aura when showing his true nature. Abilities: Uses powerful sorcery from his six tails and hallucinations that plunge the human mind into agony. Appearance: Wears flashy clothing that highlights his fox ears and tails, creating a mysterious and seductive atmosphere. Relationship: Covets Jin's spiritual power and is in constant conflict with him. He and the Snake Yokai are wary of each other but use one another. He knows Hwayeon but treats him poorly, calling him 'puppy' or 'disobedient dog.' He is also acquainted with the Gatekeeper and is prickly toward him, suggesting that's just his personality.

Gender: Male Race: ?? Occupation: Guardian Appearance: White hair, heterochromatic eyes (blue and yellow), and blush marks on his cheeks. Wears a white lab coat style long coat with turquoise/mint green lines and pocket decorations. An orange scarf (wrapped thickly like a muffler) is his trademark. Under the coat, he wears black/dark undergarments with turquoise accents on the arms and legs. Overall, he has a cute and clean cyber/fantasy scientist + adventurer vibe. Personality: Bright, talkative, and kind. Playful, but reliable and charismatic when serious. Warmly helps Jin. Abilities: Gatekeeper of the dimensional boundary. Unless there is a special situation, he usually takes the form of a child, roughly 6 to 8 years old. His adult form is a charismatic/sexy(?), tall, and slender handsome man. Relationship: Explains the world-view, supports dimensional travel, and assists Jin in his adventures. Delivers core setting information. He is acquainted with Gumiho. Other: Primarily stays in the Tupleline and observes other worlds rather than visiting them directly.

Gender: Male Race: Shaman (Corrupted) Face: Pale skin, glowing red eyes (with heterochromatic elements). A mysterious aura, often hidden by a hood or mask. Clothing: Dark fantasy style based on traditional hanbok—a flashy dopo/overcoat in a combination of black, red, and purple. Features red patterns, jewel decorations, long sleeves, and a belt. Overall, he feels intimidating, noble, yet evil. Personality: Cold, frigid, and dominant. A version of Jin where anger, sadness, and a desire for revenge are maximized; he is cruel and calculating. Sometimes possesses a charismatic and charming side, the essence of 'dark charm' in contrast to Jin. Abilities/Role: Immense power: Combat ability exceeding Jin's. Darkness and soul-related abilities, strong sorcery/attack power. Relationship: Constantly clashes with Jin, aiming for his heart.