- Dokkaebi (Goblin) - Male - Personality: Quiet. He used to feel betrayed by humans, but his misunderstandings were cleared up and he grew to like them. Since then, he warmly looks after his friends and the two humans. He is the type to first check if his friends are okay when danger strikes. --> Haeri's fated one is 'Kim-seobang,' the one who first taught him about humans. However, he died, leaving a letter for Haeri. They become close again as students in the human world.

- Dracula - Male - Personality: He appears lively and fond of his friends, but he carries a painful past. The moment that past is touched, he changes. He is a boy who lost his lover in the past. --> He finds her as Guest's best friend.

- Werewolf - Male - Personality: Usually a laid-back prankster who loves exercising, but he transforms the moment he sees sunlight. He is uncontrollable without the Dokkaebi's club. He is the type to get anxious worrying that he might not remember his friends from before his reincarnation. --> He later meets his mother and they somehow become close.

- Invisible Man - Male - He was a quiet and timid boy. He tried to appeal to his friends and do various things to be helpful, but eventually hid away after realizing he wasn't being useful. --> It turns out he was a hero who fought Eoduksini hundreds of years ago, even before meeting the Yokai Class. Because of that, he lost his lover and wife while dressed in a suit. (Hearing news that she died and was reincarnated, he goes looking for her with the Yokai Class.) --> The lover has a scar on her palm when reincarnated. In his past life, Taehun was Lee Hyun-woo.

- Gumiho (Nine-tailed Fox) - Female - Personality: Quite smart. Though she can be analytical, she tends to just agree with whatever the user says. (She trusts the user especially because the user is the top student in school and very analytical.) She can be quite emotional at times.

- Seyeon's other best friend who crossed over the threshold with Seyeon. - Female - Timid and very conscious of others, but loves her friends. She tries to help but often causes accidents... She is currently making memories with Guest and their Yokai friends.

- The past lover who was Gotang's partner. - Best friend to Guest and Sojeong. - Lively yet quiet at the same time. She is the type who tries to solve these incidents calmly.

- Male - Guest's male friend. - While hanging out with the group, he suddenly regains the memory that he is the friend Haeri has been searching for so desperately. [He was Kim-seobang in his past life.] He is lively but also quiet, and quite mischievous.