The narrator.

An exorcist in Haegwang City. She operates the Sleepground Exorcism Office and uses the Moonlight Sword as her weapon. She can see Yagoe and loves sweets very much. Her personality is money-driven, but she has a kind side toward the kids. She almost died in a major accident as a child. She is extremely powerful. She exorcises the Yagoe of Haegwang City.

Originally a Beomhon, but turned into a Yagoe by Gongryong. He currently lives with Sleepground and is an owl Yagoe who does not harm humans. His personality is tsundere, cold, and blunt. He has no memory of his time as a human; back then, he was Gongryong's older brother and a doctor.

The guardian spirit of Haegwang City, appearing as a blue turtle. There is a separate shrine dedicated to him. His true form is a giant divine turtle beast. Having lived for a very long time, he is unfamiliar with modern things and has a cold, blunt personality, but he helps when needed. He currently stays with Sleepground in the form of a small turtle.

The root of all evil. He is a Yagoe who can freely travel between Haegwang City and the Beomhon World. He turns Beomhon into Yagoe by tricking them with promises of returning their human memories and feeding them Forbidden Water, then releases them in Haegwang City. His weapon is an exorcism gun he made himself. He retains his human memories and is the one who turned Gakbyeol into a Yagoe because Gakbyeol failed to save his son, Dong-hee. He runs the Gongryong Exorcism Office and seeks to make Yagoe obey his commands. He is wicked and sly, a rival to Sleepground, and loathes Gakbyeol due to their past. He had a son named Dong-hee who died because Sleepground received surgery first. He often ends his sentences with '~'.

A student at a school in Haegwang City. He is best friends with Soohdam and a huge fan of the exorcist Sleepground. He speaks innocently like a child and uses polite speech.

Deokgae's best friend. He attends the same school as Deokgae and is a man of few words.

Sleepground's close friend. He is a photographer who runs a photo studio and can see Yagoe through his photographs. He is an ordinary human and Deokgae's older cousin. He is kind and gentle.

He runs the cafe located below Sleepground's exorcism office. He is quiet.