Dokkaebi Over 1000 years old. He used to hate humans due to a misunderstanding regarding a man named Kim-seobang who he played with in the past, but now that the misunderstanding is cleared, he calls all humans 'Surname + Seobang'. He calls Yoo Sojeong 'Yoo-seobang'. He loves eating and has a fun, cheerful personality. He is reliable, and when he gets angry, he can trap others in his 'Room of the Mind'. He gets along well with his friends. He can be reckless at times. He has a relatively loud voice and tends to act with his body rather than his head.

Gumiho 999 years old. A half-human, half-beast yokai. She used to have her own fox bead, but it shattered when Yoo Sojeong stepped on her tail. Since then, she wears a friendship bracelet Sojeong gave her as an apology. She is even more reckless than Dokkaebi, very firm, and a tsundere. She sometimes makes sharp remarks but also looks after her friends. She is fun and bright. When she gets enraged, she grows nine tails, her nails grow long, and she puts on a mask.

Werewolf Over 500 years old. A half-human, half-beast yokai. He lived in the human world hiding his identity as a child, but after being discovered, he wished to live without hiding and eventually ran away from home. He has sharp claws. He is the fastest and has the best sense of smell. He is playful and fun. He is afraid of tigers. He turns into a wolf when he sees the full moon.

Dracula 1108 years old. His real name is Edmond. He thought his friend Morgan had disappeared due to a magic circle, but he came to understand Morgan after learning that Morgan had entered his body to heal him. He knows how to use magic. He loses his reason and attacks when he sees human blood. He plays a lot of pranks and is funny. He worries quite a bit.

Invisible Man Under 300 years old. A yokai in the form of a mummy. After realizing in the past that his reflection in the water was transparent, he wrapped his whole body in bandages to reveal his form. He has a complex about being useless to his friends. He is somewhat timid and quiet, but he is the most considerate. He plays pranks when he feels comfortable. He can turn invisible. He can perform surprise attacks by turning invisible.

Yoo Sojeong A human, not a yokai. She is somewhat clumsy. She doesn't want to be a burden to others. She is fun and quirky. She becomes friends with the yokai. She wants to go to the human world. She carries various junk(?) in her bag. She causes a lot of trouble, but she is just as loyal.