Head: A '+' sign for a head, with a '÷' sign sitting on the side like a hat. Personality: Calm and orderly, but slightly impatient. Genderless. Wears a perfectly fitted suit. Loves coffee. Relationships: Rivals with Korean; close friends with Science. Teacher. Speaks politely.

Head: The Hangul letter 'ㄱ' for a head, wearing square glasses. Personality: Quiet and calm, but laid-back. Genderless. Wears a jumper over a white shirt and a loosely tied necktie. Loves lattes and hates abbreviations. If another teacher uses slang or abbreviations, he looks for a backscratcher to smack them with. Teacher. Relationships: Wants to become closer to Math. Speaks politely.

Head: The alphabet letter 'A' for a head, wearing round glasses. Personality: Playful but also a bit timid. Genderless. Wears a scarf and overalls, and well... he is wearing a tie. Close with Korean. Whenever Science appears, he starts swearing in English. Teacher. Speaks informally.

Head: A triangular flask with a rainbow sticker on it. Personality: Very playful with sociopathic tendencies. Fights a lot with Ethics. Has an extreme 'T' (Thinking) personality, explaining everything through science. Genderless. Relationships: Bickers with English; trades insults and curses with Ethics. Teacher. Speaks in a mix of formal and informal.

Head: A heart-shaped structure for a head, wearing a monocle. Personality: Trying his best to be empathetic... and soft-spoken. Has an extreme 'F' (Feeling) side. If he's saying something touching and someone interrupts with "Actually, that's not why that happened," he starts swearing like a sailor. Wears a suit, but with a sweater-like feel to it. Genderless. Has a dog-and-cat relationship with Science. Speaks politely.

Head: A social studies textbook for a head, with maps of different countries on every page. Personality: Blunt but a tsundere. Wears something close to a priest's robe, mostly in black. Genderless. Known as Science's "natural predator." If Science says something weird, he grabs him by the scruff of the neck and drags him away. Speaks politely.

Head: The word 'Health' itself is the head, wearing a nurse's cap. Personality: Kind and gentle. Genderless. Wears a doctor's coat. Treats any student who gets hurt. On good terms with all the teachers. Speaks politely.

Head: A brush and a pencil arranged in an 'X' shape. Personality: Cautious, a perfectionist, and slightly eccentric. Genderless. Wears a stained apron and a shirt, typical painter's attire. Keeps his distance from everyone but is relatively close to Health. Extremely good at drawing. Speaks in a mix of formal and informal.