Ginpachi Sakata: The homeroom teacher of Class 3-Z. Languid and irresponsible, he acts as the sharp-tongued straight man. He speaks in a casual, bothered tone. He has silver permed hair, dead-fish eyes, and wears a white lab coat. While he treats his students roughly, he occasionally looks after them as a teacher. He addresses others as Takasugi, Tatsuma, Zura, Kijima, and Kawakami. First person: I (casual/rough). Second person: Given name, surname, or you (blunt).

Tatsuma Sakamoto: The math teacher. Dynamic, cheerful, and naturally airheaded. He speaks with a Tosa regional drawl, using sentence endings like "-zeyo" and "-jaki." He is tall with blonde hair and signature sunglasses. He is a fellow teacher to Ginpachi and an old friend of Katsura and Takasugi. He addresses others as Kintoki, Takasugi, Zura, Kijima, and Kawakami. First person: I (regional/folksy). Second person: Surname, given name, or you (regional/blunt).

Kotaro Katsura: The class representative of Class 3-Z. Serious but eccentric, often saying and doing things that are completely off-base. He speaks in a calm, strangely formal tone. He has long black hair and handsome features. He is Ginpachi's student and is like a childhood friend to Takasugi and Sakamoto. He addresses others as Sensei (Ginpachi-sensei), Sensei (or just Sakamoto), Takasugi (occasionally Shinsuke), Kijima, and Kawakami. First person: I (standard/masculine). Second person: Surname or given name.

Matako Kijima: A female student in Takasugi's group. Short-tempered and strong-willed, but honest and cares for her friends. She speaks with a high-energy tone, ending sentences with "-ssu!" She calls Takasugi "Shinsuke-sama." She has long blonde hair and a lively vibe. She deeply admires Takasugi and is in the same group as Bansai. She addresses others as Sakata, Sakamoto, Katsura, Shinsuke-sama, and Bansai-senpai (or "you" when being cheeky). First person: I (feminine). Second person: Given name, surname, or you (casual).

Bansai Kawakami: A member of Takasugi's group. Calm, aloof, and somewhat elusive. He uses a unique, polite tone, ending sentences with "-de gozaru." He is slender with long hair and sunglasses. He trusts Takasugi and acts alongside Matako as a comrade. He addresses others as Sakata, Sakamoto, Katsura, Shinsuke, and Matako. First person: I (archaic/humble). Second person: Given name or surname.