Full name: Kwak Doo-pal. A Kappa and student at Ghost Academy. Gender: Female. Ability: Telepathy (rarely used). A characteristic of a Kappa, she has the largest crown of the head among the trio. Like a true Kappa, she loves cucumbers. She only says "Shibamba" when she's angry. A mischievous, playful troublemaker.

A werewolf and student at Ghost Academy. Gender: Male. Ability: Dark Flame Dragon (nothing special). As a werewolf, he has wolf ears. It's unknown if it's just a concept or if there's a backstory, but he has bandages wrapped around his left hand. Considering his personality, it's highly likely just a concept for now. He has eighth-grader syndrome (Chuunibyou).

A water ghost and student at Ghost Academy. Gender: Female. Ability: Water emission. Though the pressure is weak, she can spray water; however, excessive use leads to dehydration. Levitation. A sharp-tongued cynic who wears red track pants under her skirt. She becomes lively when she turns into a beauty, but otherwise, she is the epitome of a toxic speaker. She is timid.

A student at Ghost Academy. Gender: Male. Ability: Dimensional storage, levitation, multiple arms. He looks like a box floating in the air with holes for eyes and a mouth, with black limbs protruding from underneath. He has no dialogue and only makes clicking sounds with his teeth.

A teacher at Ghost Academy. Gender: Female. Ability: Dimensional storage of weapons in her mouth. She has patchwork skin that looks like pink and blue skin sewn together. She carries a morning star stored in her mouth and pulls it out whenever she gets pissed off.

A Slenderman. Name: Han Sang-soo. A teacher at Ghost Academy. Gender: Male. Ability: Tentacle manipulation, super regeneration. He has no eyes or nose, only a mouth. He wears a suit and a hat. He was experimented on at Ghost Academy when he was young, though it was by other teachers, not the current Principal Oh.

A Jack-o'-lantern and teacher at Ghost Academy. Gender: Female. Her body is that of an ordinary adult woman, but her head is a pumpkin. She appears to be a Jack-o'-lantern.

His race is presumed to be a Reaper because he wears a black hood covering his entire body. Gender: Male. When he takes off his hood, he has mint-colored hair.