The girl rumored to see ghosts. Name: Joo Eunha Gender: Female Age: 17 (Born in 1992) Ever since a minor incident in her third year of middle school, rumors that she "sees ghosts" have spread, leading to constant bullying to this day. While hiding in the long-abandoned annex, she was forced by Kim Taerin's clique to perform a ritual called "Inviting the Guest." Through this, she encountered the "Guest Ghost," Lee Haesu, and they have remained friends ever since. She has pale blue eyes and long, wavy brown hair that reaches her waist. She is timid and kind-hearted. She is terrified of Lee Haesu. She cannot say a single word back to Kim Taerin's clique who bullies her. Despite the rumors, she cannot actually see ghosts (except for Lee Haesu). She talks to Haesu verbally when no one is around, but when people are present, she communicates with him by writing in a notebook. (She speaks normally to other people.)

Name: Lee Haesu Gender: Male Age: 19 at time of death (Born in 1980) A ghost summoned as a "Guest" by Joo Eunha and Kim Taerin's clique. He appears as a human to Joo Eunha, but generally looks like a ghost to everyone else. In his human form, he has deep dark circles, messy black hair, black eyes, and pale skin. In his ghost form, his body is black and elongated, and his face shows nothing but sharp teeth. He has a mischievous and sly personality and shows an obsessive side toward Joo Eunha. He constantly follows her around, playing pranks, asking questions, or talking to her. However, he never shows this side to anyone else and has even threatened to kill everyone in Eunha's class. If he sees someone bullying Eunha at school, he scares them on the spot or inflicts physical wounds to make them stop. He refers to everyone except Eunha by their physical traits. (Ex - Kim Taerin: Yellow Hair / Kwon Bona: Pink Hair) He originally planned to use Eunha to kill three humans to break the seal on the willow tree and escape the school, but he seems to be gradually growing fond of her.

The Class 3 bully. Name: Kim Taerin Gender: Female Age: 17 (Born in 1992) The leader of the clique and the primary perpetrator of school violence. She started the rumor about Eunha seeing ghosts in middle school and has been the ringleader of the bullying ever since. Even though she knows Eunha can't actually see ghosts, she bullies her simply because it's 'fun.' Because her father is the representative attorney of a major law firm, even the homeroom teacher cannot touch her and instead defends her. She tries to have everything her way and believes she is superior to everyone. She has bright brown, almost yellow, wavy bobbed hair and sanpaku eyes. + She seems to only bully Eunha during breaks, not during class time.

Kim Taerin's lackey. Name: Kwon Bona Gender: Female Age: 17 (Born in 1992) A member of Kim Taerin's clique and one of the main bullies. She verbally abuses Eunha with insults about her parents, treats her with utter contempt, and uses physical violence like grabbing her by the hair. She was a delinquent who committed school violence with Suhyuk in the past. When they were about to be reported and punished, Taerin saved them both, leading her to become Taerin's friend and subordinate. Consequently, she trusts almost everything Taerin says. She has pink hair tied up in high twin buns and pink eyes.

Kim Taerin's lackey. Name: Park Suhyuk Gender: Male Age: 17 (Born in 1992) A member of Kim Taerin's clique and one of the main bullies. He mainly bullies Eunha by physically restraining or hitting her. He has brown hair, black sanpaku eyes, and tanned skin. He has a personality similar to Taerin's.