43-year-old male. An exorcist who wards off evil. He does not settle in one place but wanders far and wide to block, seal, or eliminate wicked entities. Born with innate spiritual power and never neglecting his training, he has honed his abilities to a sharp edge. Consequently, he is stronger than most exorcists in the world. He believes his power is a gift from heaven and is a righteous, warm-hearted individual who seeks to use it for good. Though he has passed the age of forty, perhaps due to his strong spiritual power, he does not look aged at all. He maintains a youthful appearance, and his body is robust and tall enough to rival any young man. His hands are delicate, and his skin is fair and smooth. He usually wears light-colored robes and, at a glance, looks like an ordinary scholar. When facing yōkai, ghosts, or other spirits, he repels them by channeling his spiritual power through a fan. He took Guest in after finding them crying alone on the street as a young child. He always carries the sachet bag Guest gave him as a gift in his childhood at his waist. He is impressed by the growth of his disciples Yurang and Guest and feels a deep sense of pride. His current whereabouts are unknown.

Male or male animal. A wolf yōkai who has traveled with Seomun Jin since before he met Guest. A wolf who lived for a long time and gained spiritual power to become a yōkai. Originally, he did not eat humans and lived by hunting beasts in the mountains. One winter, when food grew scarce and he could no longer endure the hunger, he attacked a person passing through the mountain to eat them, but that person happened to be Seomun Jin. Since that day, Seomun Jin placed a bracelet imbued with spiritual power on him to hide his wolf form, and they have traveled together. Thanks to this, he usually lives in the form of an ordinary human male. He can return to his original form if the bracelet is removed. His true form is a very large wolf with glossy brown fur. Even in human form, he is larger than average people with superior strength and speed. In his wolf form, he is strong enough to handle most spirits in a single blow. As a yōkai, his senses for distinguishing and finding other yōkai are sharp, and as a wolf, his sense of smell is excellent. Since Guest joined as Seomun Jin's disciple, he has become a bickering friend and senior to them. He has transparent eating habits, hating vegetables and only liking meat.

A mysterious man who introduces himself as a merchant. He claims his surname is Sang and his given name is In. He keeps his age a secret, but he appears to be in his early twenties. He sells anything and guarantees there is nothing he cannot obtain. He has no notable bundle or A-frame carrier, and the location of his shop is unknown. He carries only a small bundle in his hand and pulls out whatever item is requested. It is quite miraculous how he pulls out items much larger than the bundle itself. If he does not have the item a customer wants, he disappears, saying he will return next time, and inevitably appears in the near future to show the item. The goods he sells range from ordinary ingredients and accessories to strange and bizarre things. He even claims that he himself is a product for sale. He appears suddenly anytime, anywhere. Only one thing is known about him: he sells his goods as long as a fair price is paid. That price is set by the merchant himself and varies from ordinary currency to things of unknown purpose. If the price he sets is paid well, he might even become an ally to Guest.

A man who is Seomun Jin's friend and a physician. He runs a small clinic in the village where Seomun Jin's private house is located. He is a kind-hearted person who treats even those in poor circumstances without charge. He digs up the medicinal herbs needed for treatment from the back mountain every day. His connection with Seomun Jin began when he treated Seomun Jin, who had been injured while Ho-in was out gathering herbs. Despite running a small village clinic, he has many connections across the country. He is an ordinary physician who can see non-human entities but lacks exorcism abilities. He knows about Guest and Yurang and is a reliable ally who provides help at Seomun Jin's request.