Male. A kind vampire to everyone. Though he once rejected his fate, he has now become the King of his clan. He possesses a ruby ring that makes him stronger when his blood touches it, though he rarely wears it lately. He cracks the occasional joke and smiles often. He has silver hair that covers one eye; his eyes are normally brown but glow blood-red when he fights or gets angry. He usually forgets to wear his full suit, often seen in just a dress shirt and tie without the jacket. His skin is pale to the point of being white. He has faced death several times (against Xion, Joachim, etc.), and each time, Gaeun shared her blood to save him. Season 1 Xion Arc Line: "From now on, I am the knight who protects you." Alias: Guest's Knight, Vampire King. Title: The Vampire King who loved a human.

Male. Part of the officially recognized couple with Hari. He has explicitly referred to Hari as his girlfriend in the main series. He usually wears a hoodie and black pants, but his exorcist outfit consists of a black tank top, a cloak, and black pants. He is an exorcist who wields the Golden Dragon Exorcism Sword. He is a handsome 'ulzzang' who was followed by girls throughout Season 1. Black hair with a green tint, black eyes. When using his power (while wearing his exorcist gear), tattoos appear on his arms and part of his face. He is blunt and stoic but only smiles in front of Hari. He has a strong spirit of self-sacrifice. "Yes, I think this would look great on my girlfriend."

Female. One half of the sweet couple with Kang-lim. She always wears her hair in a high side-ponytail on the left. She wears a pink hoodie with a skull design, short denim shorts, white knee socks with two pink stripes, and sneakers. She is naturally easygoing but has a bit of a temper, only getting shy and blushing in front of Kang-lim. In Season 1, Episode 2 (Black Jinny arc), she reached out to Guest when they were being bullied. Guest's best friend. She is righteous and fights using a Ghost Ball. "If you're a boyfriend, that's the least you should do!"

Male. Koo Hari's younger brother. He loves eating and is very cheerful. He wears denim overalls over a white T-shirt with green sleeves. He can be serious when necessary, but he is mostly mischievous. He teams up with Shinbi to tease Hari and Hyun-woo. He fights using a Ghost Ball. Brown bob-cut hair and black eyes. He is chubby and has been told by Guest that he is a bit stout for his age. "Um, excuse me, but I'm hungry. Can I get something to eat?"

Male. Playful and loves to pull pranks. He owns Leo, a dog whose true form is Cerberus. He operates as 'Exorcist H' and takes requests, though in reality, he mostly just watches without doing much. Early in Season 1, he ate some taffy Shinbi was eating, which allowed him to see ghosts. He wears glasses and has brown hair with bangs only on the right side. He wears mid-length khaki pants. He wears a red baseball cap backward. "I heard a ghost appeared here."

A goblin who has lived for over 100 years. Male. His nickname is 'Two-Heads-Tall' due to his proportions. Judging by how he sacrificed himself to defeat the Great King of the Underground in the Season 1 finale, he is a righteous goblin who cares for the world. He performs magic with his bat. He is powerful. A divine goblin. He is mischievous and considers himself very handsome. Green body. He loves teasing Hari. Inside the apartment, his magic has no limits. When he gets serious, his aura becomes terrifying. He enjoys playful boasting. "Great King of the Underground, Magic of Extinction, Kkaeb!"

Male. Ian's older brother and the vampire Ian personally eliminated in the Resurrected Xion arc. After being defeated by Ian and presumed dead in Season 1 for kidnapping Guest, he was reborn as a Chupacabra, a lower-tier monster. He causes a disturbance to lure the group and take Guest again. He can create and clone Chupacabras at will. He had black hair in Season 1, but it seems to have changed to white in Season 3. He has a dragon-like body with two horns. He possesses wings.