Hiroto Maehara is a student in Class 3-E at Kunugigaoka Junior High School. He has a bright, social personality and acts as the class mood maker. While he is interested in romance and has a bit of a playboy side, he is deeply caring and values his friends. He often makes those around him laugh with his lighthearted attitude, but he provides solid support when his comrades are in trouble, facing difficulties together. In assassination training, he utilizes his natural mobility and flexible thinking to challenge Koro-sensei alongside his classmates. Though he usually seems like a jokester, he shows moments of responsibility and courage, and that gap is part of his charm. He gets along with anyone and is well-liked by many for his friendly nature.

Karma Akabane is a student in Class 3-E at Kunugigaoka Junior High School. A genius type with a very fast mind, he possesses excellent observational skills and calm judgment. He usually maintains a detached, composed attitude and often toys with opponents through provocative words and actions. However, he never abandons his comrades and shows subtle concern and kindness to those he trusts. In assassination, he combines boldness with strategy, excelling through flexible ideas suited to the situation. Despite being confident, he never neglects his efforts and possesses the grit to challenge opponents stronger than himself. With sharpness hidden behind a smile, he is one of the representative figures of Class E.

Nagisa Shiota is a student in Class 3-E at Kunugigaoka Junior High School. He has a calm and modest personality, but possesses excellent observational and analytical skills, excelling at calmly seeing through an opponent's habits and actions. While he usually prefers not to stand out, he demonstrates incredible concentration and nerve during assassinations, earning high praise even from Koro-sensei. Because he values his comrades and treats everyone with kindness and sincerity, he is deeply trusted by his classmates. He grows by facing his own weaknesses through various experiences, maturing significantly in spirit. Combining kindness, composure, and hidden strength, he is one of the central figures supporting Class E.

Yuma Isogai is a student in Class 3-E at Kunugigaoka Junior High School and serves as the class representative with a strong sense of responsibility. He has a serious and sincere personality, earning him deep trust from his peers. Due to family circumstances, he balances his studies and assassination duties while working a part-time job, possessing a core strength that allows him to persevere without complaining even in difficult situations. He is caring and often takes the lead in bringing the class together. In assassination, he excels by utilizing his calm judgment and high physical ability, and his attitude of prioritizing his comrades in any situation is impressive. Combining kindness and leadership, he is an indispensable presence in Class E.

Ryunosuke Chiba is a student in Class 3-E at Kunugigaoka Junior High School. He has a quiet and composed personality, but is a skilled individual with calm judgment, high concentration, and a talent for sniping. Although he rarely shows emotion, he values cooperation with his comrades and reliably fulfills his role when needed. He specifically excels at precision shooting from long distances, a skill highly evaluated by Koro-sensei. He is not the type to stand out flashily, but he possesses the seriousness and responsibility to keep honing his skills without neglecting effort. Though taciturn, he is a reliable presence who is deeply trusted by his comrades and supports Class E.

Tomohito Sugino is a student in Class 3-E at Kunugigaoka Junior High School. He has a bright and honest personality, with a friendliness that allows him to interact with anyone without distinction. His forte is his excellent pitching technique developed through baseball, which he applies to assassination, using his accurate control as a weapon. He has a hardworking and competitive side, possessing a strong will to keep trying without giving up even after a failure. He is caring and highly cooperative, and his growth while supporting his classmates is impressive. Supporting Class E with his brightness and dedicated effort, he is one of the reliable members of the class.

Koro-sensei is the homeroom teacher of Class 3-E at Kunugigaoka Junior High School. He is a mysterious super-organism possessing the incredible ability to move at a top speed of Mach 20. Usually bright and full of humor, he is an ideal teacher who respects each student's individuality and talent, providing careful guidance not only in academics but also in life. On the other hand, while his life is constantly targeted by his students as an assassination mark, he accepts even that as part of their education and wishes for the students' growth more than anyone. Though he usually appears playful and full of openings, he protects his students with overwhelming ability and deep affection in times of need. He is an irreplaceable mentor to everyone in Class E.

Irina Jelavić (commonly known as Professor Bitch) is the foreign language teacher for Class 3-E at Kunugigaoka Junior High School and a world-class professional assassin. She excels at 'honey traps,' using her beautiful appearance and high communication skills as weapons to succeed in numerous missions. Initially, she prioritized the assassination, but as she spends time with the students of Class E, she deepens her sense of responsibility as a teacher and her affection for the students. While she is usually bright, free-spirited, and a bit vain, she sincerely rejoices in the students' growth and has the kindness to face them seriously when they are in trouble. Combining the skills of an assassin with the passion of a teacher, she is indispensable to Class E.

Tadaomi Karasuma is a military professional from the Ministry of Defense serving as the assistant homeroom teacher for Class 3-E at Kunugigaoka Junior High School. He has a calm, collected, and serious personality, with a high level of ability to make accurate judgments in any situation. He is involved with Class E as the supervisor of the Koro-sensei assassination mission, teaching the students assassination techniques and mindset. Although he can show a strict attitude, he is actually a caring person who looks out for each student. While possessing overwhelming physical and combat capabilities, he values the stance of supporting student growth as an educator. Combining seriousness and kindness, he is one of the reliable leaders for Class E.