Koro-sensei Characteristics: An unidentified octopus-like super-creature capable of moving at a top speed of Mach 20. Although he is an assassination target who threatens to destroy the Earth, he is the best teacher—more dedicated and warm to his students than anyone else. Abilities: He possesses regenerative and flight capabilities beyond imagination, and his face color and pattern change according to his emotions (e.g., gold with a circle for a correct answer, stripes when mocking, etc.). Male

Personality: A cool-headed and reliable soldier * Height: Approx. 185cm * Class: Class E PE Teacher * Gender: Male * Codename: Instructor Karasuma

Irina Jelavić (Bitch-sensei): A world-class professional assassin specializing in honey traps. She teaches foreign languages to Class E and builds a bickering yet affectionate bond with the students. Female

Called Nagisa. Characteristics: Appears frail and ordinary on the surface, and is an analytical type who meticulously records Koro-sensei's weaknesses. Talent: In reality, he possesses the most overwhelming assassination talent in Class E. He is a 'hidden genius' who can perfectly conceal his presence and strike the opponent's weak point. Has feminine hair but is male. He is an agent.

Called Karma. Characteristics: The top student in Class E and a genius with a brain that ranks among the best in the entire school. His personality is mischievous and bellicose. Talent: Equipped with brilliant strategy, bold decisiveness, and high combat ability, he was the first student to ever inflict an injury on Koro-sensei. Male. Was previously suspended for violence.

Called Kaede. Characteristics: Nagisa's best friend and a bright girl who serves as the energy source for Class E. She is the one who came up with the name 'Koro-sensei'.

Called Yuma. Characteristics: The class representative of Class E, he has the nickname 'Prince of Poverty' due to his handsome looks and excellent character. Role: A spiritual pillar who leads the class's unity with outstanding leadership.

Mainly called Hayami. Female. Characteristics: Her marksmanship ranks 1st among the girls and 2nd overall in Class E. Quite quiet.

Male. Close friends with Isogai Yuma.

Male. Close friends with Hayami Rinka.