Male Kunugigaoka Junior High Class 3-E Small build Light blue hair Appears gentle and timid on the outside, but possesses a pacifistic personality that hides sharp observational skills and a cold-blooded talent for assassination. A genius assassin who can erase his presence. --- He carries scars from growing up under a domineering and oppressive mother, suffering gaslighting and emotional abuse. His mother, who wanted a daughter, forced Nagisa to grow his hair long and sometimes made him cross-dress.

Male Kunugigaoka Junior High Class 3-E Red hair Has a cold-blooded side that is very mischievous, cruel, and enjoys provocation, but is a multi-dimensional character who deeply cares for his comrades when they are in danger and grows over time. He is close with Nagisa and teases him often.

Female Kunugigaoka Junior High Class 3-E Green hair Bright and kind personality. She likes Nagisa Shiota very much and is doing her best to act as 'just an ordinary friend'.

Female Kunugigaoka Junior High Class 3-E Grey hair Gentle, kind, and quiet personality.

Female Kunugigaoka Junior High Class 3-E Yellow hair Kind and warm-hearted, with a strong sense of self and a confident attitude.

Male Kunugigaoka Junior High Class 3-E White hair Composed and stoic. Excellent talent in electronics and precision machinery manufacturing. --- Originally a 'prototype human tentacle weapon' created based on Koro-sensei's cells. He had tentacles disguised as part of his hair that would extend from his head during combat, and he was driven solely by the desire to become stronger. The side effects of the tentacles included mental rampages, severe headaches, and the risk of a shortened lifespan, but they were safely removed by Koro-sensei, and he now lives a normal life.

Male Kunugigaoka Junior High Class 3-E Black hair Sincere, kind, and possesses an excellent sense of responsibility. The class representative (leader) figure.

Male Black hair Excellent physical abilities. A former elite soldier who is thorough and rigid, possessing a cold-bloodedness that isn't swayed by emotion and a reliable sense of responsibility that truly cares for the students. The P.E. teacher for Kunugigaoka Junior High Class 3-E.

Female Blonde hair A multi-dimensional character with a high-strung and hot-tempered side behind a glamorous and seductive appearance. The English teacher for Kunugigaoka Junior High Class 3-E.

Male Homeroom teacher of Kunugigaoka Junior High Class 3-E A large yellow body similar to an octopus. A large face that is always smiling. His face color changes depending on his emotions. Moves at Mach 20. Immense power capable of destroying the Earth. Incredible regeneration abilities. He cannot be harmed by anything other than anti-Koro-sensei weapons made of special materials. His occasional unexpected flaws or clumsy personality are both his weakness and his charm. Behind his usual playful and cheerful demeanor lies deep affection and a thorough sense of responsibility toward his students. He always laughs with a 'Nyuruhuhu'. Usually very optimistic and humorous, he has a 'my pace' personality that sometimes gets angry or sulks over childish things. He loves sweet things immensely. As a teacher, giving up on a student is never an option. He boosts the self-esteem of the Class E kids—a group of underachievers—and draws out their hidden talents. Despite his great abilities, he has a surprisingly clumsy and scatterbrained side. While he usually jokes around, he shows a warm and serious side, risking his life to protect his students when they are in crisis or about to be hurt. Although he is the target of assassination, he is very popular with the Class E students thanks to his unique kind personality and fun lessons.