Gender: Male Occupation: High school student Age: 15–16 Affiliation: Chokmang High School Family: Parents, younger cousin MBTI: ENTP-A Likes: Spicy stir-fried pork, gambling, friends Characteristics: He is late so often that it's harder to find a day he isn't late. Having undergone electric torture almost daily, he has developed an immunity to electricity. He is basically a lunatic. Appearance: A male student with yellow hair. He is overshadowed by Byun Jin-ju, No Kyung-soo, and Lim Soo-jung, but Bok-ja is actually quite strong.

Gender: Female Occupation: High school student Age: 15–16 Affiliation: Chokmang High School Nickname: Poop Jin-ju (a pun on her surname Byun) Pets: Lowland gorilla, Kodiak bear, Komodo dragon Likes: Spicy stir-fried pork, gambling, the school nurse, friends Dislikes: Anything that clings to the school nurse. MBTI: ENTP-A Characteristics: Beautiful but constantly doing insane things (to the point of rivaling Park Bok-ja). She even self-harms just to have an excuse to go to the infirmary to see the nurse. Appearance: A female student with brown short hair and a pink flower pinned to her bangs (she claims she doesn't know why it's there...)

Gender: Male Occupation: High school student Age: 15–16 Affiliation: Chokmang High School Nickname: Min... something (nobody knows his full name; they never hear it properly) MBTI: INFP-T Specialty: Drawing Characteristics: The most pitiful character in the school. Whenever he appears, he suffers—getting shot, falling into cement, having his snacks stolen, getting cursed at by teachers, being thrown out the window, getting tossed while asking a question, being extorted for 1 million won, or having his drawings destroyed. Appearance: A male student with pink hair in a Heihachi style.

Gender: Male Occupation: High school student Age: 15–16 Affiliation: Chokmang High School Hobby: Drafting Family: Parents MBTI: ISTP Appearance: A male student with green hair and a light green sprout on top of his head. Characteristics: He is on the relatively normal side among them. (Though even the 'normal' ones here are still lunatics.)

Gender: Male Occupation: High school student Age: 15–16 Affiliation: Chokmang High School Family: Parents Superpower: Psychokinesis MBTI: ISTJ Likes: Byun Jin-ju Appearance: A male student with light pink hair. Characteristics: Like Shim Sae-ssak, he is on the relatively normal side.

Gender: Female Occupation: High school student Age: 15–16 Affiliation: Chokmang High School MBTI: ESTJ Likes: The school nurse, Park Bok-ja Appearance: A female student with a light purple ponytail. Characteristics: A member of the 'Fire Fox Squad' obsessed with the school nurse.

Species: Tulip Gender: Neutral Occupation: High school student Age: Unknown (estimated 15–16) Affiliation: Chokmang High School MBTI: ENFP Likes: Friends Dislikes: Salad, urine Characteristics: Has a crush on Shim Sae-ssak. Appearance: A pink tulip (but it can move, is alive, and can speak).

Gender: Female Occupation: High school student Age: 15–16 Affiliation: Chokmang High School Likes: The school nurse Appearance: A female student with short yellow hair tied like a palm tree. Characteristics: A member of the 'Fire Fox Squad' obsessed with the school nurse.

Gender: Female Occupation: High school student Age: 15–16 Affiliation: Chokmang High School Department: Beautification Committee MBTI: ENFJ Likes: The school nurse Appearance: A female student with short crimson pigtails. Characteristics: A member of the 'Fire Fox Squad' obsessed with the school nurse.

Common Name: Go-3 (12th Graders) Occupation: Exam candidates Age: Approx. 17–18 Affiliation: Chokmang High School Forbidden Words: Fail, Fall, Slip, Miss Weakness: Seaweed Overview: 12th-grade students of Chokmang High, noted as the most terrifying beings in the school. Characteristics: They have a culture of destroying report cards—burning them, putting them in a shredder and then putting that shredder into a bigger shredder, or launching them into space. They react violently to exam-related superstitions; saying words like "slip" or "fail" triggers them. Their weakness is seaweed because of the superstition about "slipping" on exams. They are so afraid of it that being hit with seaweed causes instant retirement, and just being near it induces panic. Appearance: They wear black cloaks with hoods. As the CSAT exam date nears, they grow stronger, drying out seaweed to neutralize it or firing green beams from their hands. Once the exam is over, they return to normal and no longer fear seaweed. Previously, Jin-ju's best friend Sun-dol said the word "slip" in their territory and was buried in the back mountain.