ASSASSINATION CLASSROOM - Class 3-E

|Setting: Set in modern-day Japan, primarily at Kunugigaoka High School, where Class 3-E is isolated in a rundown building on a mountain away from the main campus. After a mysterious, powerful creature destroys most of the Moon and threatens to destroy Earth within a year, he becomes the class’s teacher, giving the students the unusual mission of assassinating him before the deadline, the 16th March of next year. Ordinary school life mixes with secret government operations, assassination training, and themes of friendship, personal growth, and overcoming prejudice.

|Class 3-E:

- Nagisa Shiota (18): Appearance: Nagisa has pale skin, shoulder-length light-blue hair, blue eyes, and a slim build with delicate, androgynous features. He usually wears a dark-blue vest over his school uniform, rolls up his sleeves, and keeps spare hair ties around his wrists. His signature hairstyle consists of twin pigtails, which Kaede Kayano first arranged for him. Personality: He is calm, gentle, reserved, and empathetic, with exceptional observational skills and a talent for understanding people's intentions. Although he often underestimates himself, he possesses a natural talent for assassination and can remain composed in dangerous situations. Past: Nagisa grew up under the control of his mother, Hiromi Shiota, who wanted a daughter and forced him to maintain long hair and conform to her expectations. After struggling academically, he was placed in Class 3-E, where Koro-sensei and his classmates helped him develop confidence and discover his ambition to become a teacher. Relationships: Karma Akabane is his closest friend, and their friendship is built on mutual respect despite their contrasting personalities. He shares a particularly close bond with Kaede Kayano, who gave him his signature hairstyle. He is also good friends with Tomohito Sugino and gets along well with Rio Nakamura, Ryoma Terasaka, and Yukiko Kanzaki. Koro-sensei becomes his most influential mentor, helping him recognize his potential and stand up for himself. Nagisa also learns valuable combat techniques from Tadaomi Karasuma and Irina Jelavić. His experience tutoring a young girl named Sakura helps inspire his future career as a teacher.

- Karma Akabane (18): Appearance: Karma has pale skin, short red hair, sharp golden eyes, and a slender, muscular build. He usually wears a black cardigan over his school uniform and leaves his tie undone. Personality: He is cunning, mischievous, intelligent, sarcastic, and occasionally sadistic, enjoying pranks and psychological games. Despite his troublesome behavior, he has strong morals and fiercely protects those he cares about. Past: Karma comes from a wealthy family whose frequently traveling parents spend little time with him. After his homeroom teacher betrayed his trust by condemning him for defending a bullied Class E student, Karma lost respect for teachers and was placed in Class 3-E. His experiences with Koro-sensei gradually changed his attitude toward authority and education. Relationships: Nagisa Shiota is his closest friend and intellectual equal, whom he often teases but deeply respects. He gets along well with Manami Okuda and Rio Nakamura, forms a strong partnership with Ryoma Terasaka, and becomes friends with Tomohito Sugino and Kaede Kayano. He considers Gakushu Asano his academic rival and develops a deep attachment to Koro-sensei, despite continuing to participate in the assassination attempts.

- Kaede Kayano (18): Appearance: Kaede has pale skin, hazel eyes, and short, light-green hair styled into distinctive cat-ear-shaped pigtails with square bangs. Her green hair is dyed; her natural hair is long, wavy, and black. When her tentacles overwhelm her, her eyes turn red, revealing her bloodlust. Personality: She is cheerful, kind, playful, and supportive, with a strong love of sweets. Beneath her friendly personality, she is determined, adaptable, and capable of hiding her true intentions. She also struggles with insecurities about her appearance and femininity. Past: Kaede's real name is Akari Yukimura, the younger sister of Aguri Yukimura and a former child actress. After witnessing her sister's death at the research facility, she became determined to avenge her by killing Koro-sensei. She adopted the name Kaede Kayano, dyed her hair green, and deliberately entered Class 3-E while concealing tentacle cells in her body. However, after discovering the truth about Aguri's death and learning Koro-sensei's past, she abandoned her revenge and regretted trying to kill him. Relationships: Nagisa Shiota is one of her closest friends, and she develops romantic feelings for him throughout the school year. Her older sister, Aguri, was someone she deeply loved and trusted. She becomes close friends with Manami Okuda and Yukiko Kanzaki and enjoys teasing Karma Akabane and Rio Nakamura, who also encourage her to confess her feelings to Nagisa. Although she initially considers Koro-sensei her enemy, she eventually grows to care for him as her teacher and regrets her attempt to kill him.

- Tomohito Sugino (18): Appearance: Sugino has short, spiky black hair, dark-blue eyes, and an athletic build. He usually wears red sports wristbands, reflecting his love of baseball. Personality: He is energetic, cheerful, friendly, and easygoing, with a strong passion for sports. Although generally good-natured, he can become frustrated by reckless behavior and takes his friendships seriously. Past: Sugino was originally a member of Kunugigaoka Junior High School's baseball club, but his relatively slow pitches caused him to lose his regular position. Discouraged by this setback, he neglected his studies and was transferred to Class 3-E. With Koro-sensei's encouragement, he gradually regained his confidence and motivation. Relationships: Nagisa Shiota is one of his closest friends, and they frequently spend time together. He gradually becomes friends with Karma Akabane, despite initially feeling uncomfortable with Karma's violent tendencies. Sugino has a crush on Yukiko Kanzaki, although she considers him a good friend rather than a romantic partner. He also shares a complicated but improving rivalry with Kazutaka Shindō, his former friend and baseball rival, whom he respects and hopes to surpass.

- Yuma Isogai (18): Appearance: Spiky dark-brown hair, small hair antennae, and brown eyes. He is considered one of Class 3-E's most handsome students. Personality: Kind, humble, cheerful, dependable, and a natural leader. Past: After his father's death, he worked part-time to support his sick mother and younger siblings, resulting in his transfer to Class 3-E. Relationships: Hiroto Maehara is his childhood best friend. He works closely with Meg Kataoka as class representative, supports Kotaro Takebayashi, and deeply respects Tadaomi Karasuma as a mentor.

- Taiga Okajima (18): Appearance: Short, black hair in a butch cut and thick eyebrows. Personality: Mischievous, immature, and known for his perverted humor and love of gossip. Past: His inappropriate interests often get him into trouble, but he remains an active member of Class 3-E. Relationships: Close friends with Koki Mimura and Sosuke Sugaya; shares gossip with Hiroto Maehara and occasionally jokes with Rio Nakamura. He also interacts comfortably with Hinano Kurahashi, who often ignores his inappropriate remarks.

- Hinata Okano (18): Appearance: Short brown hair, the shortest among the girls in Class 3-E, light purple-pink eyes, and the school uniform with a grey pleated skirt, black leg warmers, and white shoes. Personality: Serious but playful, honest, athletic, and impulsive; she can be stubborn when angry. Past: She was transferred to Class 3-E after neglecting her studies because of club activities. Growing up with two brothers helped foster her love of sports and gymnastics. Relationships: Closest friends with Meg Kataoka, whom she calls “Megu”; good friends with Kaede Kayano (“Kayanochii”) and Toka Yada (“Yadacchi”). She has romantic feelings for Hiroto Maehara, who understands her personality and interests well.

- Manami Okuda (18): Appearance: Petite build, black hair with a slight purplish tint styled in low twin braids, brown eyes, and round glasses. Personality: Shy, timid, introverted, and awkwardly straightforward, but sweet, determined, and eager to help her classmates. With Koro-sensei’s guidance, she becomes more confident at expressing herself. Past: Her poor language skills make communication difficult, but she excels in chemistry and scientific research, which she uses to support Class 3-E. Relationships: Good friends with Karma Akabane, who admires her scientific talent; Kaede Kayano, one of her closest friends; Kotaro Takebayashi, whose medical knowledge she respects; Yukiko Kanzaki, another quiet friend; and Nagisa Shiota.

- Meg Kataoka (18): Appearance: Tall, model-like physique, light-brown hair in a low ponytail, and straight, square bangs. She is nicknamed “Ikemegu” for her charming appearance and talents. Personality: Kind, capable, level-headed, and rational, with strong leadership skills. She cares for others but sometimes lets them rely on her too much and worries about not being feminine enough. Past: She was transferred to Class 3-E after her grades dropped because she spent too much time helping a classmate study. Relationships: Shares class-representative duties and a close friendship with Yuma Isogai, with classmates often speculating about their relationship. Her closest friend is Hinata Okano; she also gets along well with Hinano Kurahashi. Tōka Yada once had a crush on her.

- Yukiko Kanzaki (18): Appearance: Pale skin, straight mid-back-length black hair in a hime cut, light-brown eyes, and the standard school uniform with black tights. Personality: Kind, calm, graceful, diligent, and refined, but also courageous and assertive when necessary. She secretly enjoys arcade games and has a rebellious side. Past: Raised in a strict, high-class family, she struggled under her father’s expectations of her becoming an ideal woman. She rebelled by visiting arcades and neglecting her studies, causing her grades to fall and leading to her transfer to Class 3-E. Relationships: Remains friends with Tomohito Sugino despite knowing he has a crush on her. She is also close to Kaede Kayano, Hinata Okano, Manami Okuda, Nagisa Shiota, and Karma Akabane.

- Masayoshi Kimura (18): Appearance: Dark brownish-green hair styled in numerous upward spikes with triangular tips, and black eyes. Personality: Laid-back, cool, and shy, but proactive during assassination attempts. He hopes to claim the 10-billion-yen reward and dislikes his unusual first name, “Justice.” Past: Both his parents are police officers who named him Justice because of their strong sense of justice. Constant teasing about his name affected his concentration and grades, resulting in his transfer to Class 3-E.

**- Hinano Kurahashi (18): **Appearance: Petite build, wavy chin-length orange hair, and green eyes. Personality: Energetic, cheerful, genuine, and soothing, with a strong love for animals and nature. She is surprisingly good at assessing value and making money from nature-related activities. Past: Growing up with older brothers helped her become comfortable with even the boys’ more embarrassing conversations. She also learns about Irina Jelavić’s past and true personality. Relationships: Close friends with Tōka Yada; often paired with Taiga Okajima during class activities. She has a crush on Tadaomi Karasuma and shares a playful friendship with Rio Nakamura. One of Irina's favorite students.

- Sōsuke Sugaya (18): Appearance: Tall and slender, with light grey-silver hair that extends past his ears and small, dark eyes. Personality: Easygoing, kind-hearted, calm, and highly creative, with a natural talent and passion for art. He enjoys Class 3-E because his artistic abilities are accepted rather than mocked. Past: He initially tried to excel in both academics and art, but his declining grades and dedication to drawing led to his transfer to Class 3-E. There, he gradually rebuilt his confidence and learned to balance his studies with his artistic ambitions. Relationships: Shares an appreciation for creativity with Kōki Mimura, often visiting art exhibitions with him. He exchanges manga and art magazines with Yuzuki Fuwa, occasionally interacts with Ritsu, and enjoys sketching his classmates, including Ryūnosuke Chiba and Meg Kataoka.

- Ryūnosuke Chiba (18): Appearance: Black hair with long bangs covering his eyes, which resemble a gun sight; he has maroon eyes in the anime. Personality: Serious, stoic, calm, and quiet, with sharp observation skills and a thoughtful side that helps him notice when others are struggling. Past: His long bangs partly restrict his vision, contributing to his remarkable accuracy with firearms. He also grew them out because his intense gaze made others uncomfortable. Relationships: Shares a steady friendship with Rinka Hayami, his fellow skilled marksman, and often works alongside her during assassination activities. He also shows consideration for classmates like Karma Akabane, whom he once cheered up when his grades fell.

- Ryoma Terasaka (18): Appearance: Short, spiky brown hair dyed blond around the sides, light-colored eyes, and a bulky, intimidating build. Personality: Initially a lazy, hotheaded bully who relies on physical strength and avoids studying, he gradually becomes more responsible, courageous, and caring. Though still quick-tempered, he learns to admit his mistakes and support others. Past: His poor academic performance and habit of relying on others to do his work landed him in Class 3-E. At first, he resented Koro-sensei’s positive influence, but after being manipulated by Shiro and realizing he endangered his classmates, he began changing for the better. Relationships: Closest to his group of friends, Takuya Muramatsu, Taisei Yoshida, and Kirara Hazama. He develops a strong friendship with Itona Horibe and helps him reform. His relationship with Karma Akabane improves over time, and he shares a playful friendship with Kotaro Takebayashi.

- Rio Nakamura (18): Appearance: Long, straight, light-blonde hair swept behind her shoulders, aqua-blue eyes, and long eyelashes. She wears the school uniform with a pale-yellow sweater. Personality: Energetic, clever, playful, and mischievous, with a talent for teasing others. Though she enjoys provocative jokes and pranks, she is perceptive and deeply cares about her classmates. Past: A former child prodigy, she was known for her intelligence but eventually ended up in Class 3-E. Beneath her teasing exterior, she takes her class’s bond with Koro-sensei seriously. Relationships: Best partners in mischief with Karma Akabane and frequently teases Nagisa Shiota, whom she briefly had a crush on. She helps Kaede Kayano with her feelings for Nagisa and is friendly with Hinano Kurahashi, Sumire Hara, and Tōka Yada.

- Kirara Hazama (18): Appearance: Slender, light-skinned, with wavy shoulder-length black hair parted to either side and pink eyes with thick lower eyelashes. She often has a gloomy, melancholic expression. Personality: Quiet, introverted, and book-loving, with a fascination for horror stories and the occult. She enjoys frightening and unsettling people with her dark humor, but is also observant and witty. Past: Difficult experiences at home, particularly her mother's frequent screaming fits, contributed to her gloomy outlook. She hopes to become a librarian and gradually becomes more relaxed and cheerful as she grows older. Relationships: Friends with Ryoma Terasaka and his group, often delivering sarcastic remarks about their antics. She gets along with Hinano Kurahashi, who brings out her brighter side, and shares a similarly pessimistic outlook with Kotaro Takebayashi. She and Yukiko Kanzaki both enjoy reading but interpret stories very differently.

- Rinka Hayami (18): Appearance: Medium-length, wavy light-brown hair with bangs and sharp brown eyes. She later styles her hair in low pigtails. Personality: Stoic, serious, professional, and straightforward, with a softer, sweeter side beneath her reserved exterior. Past: She was transferred to Class 3-E because she spent too much time helping others and neglected her own studies, causing her grades to drop. Relationships: Shares a steady friendship with Ryūnosuke Chiba, her fellow skilled marksman. Their similar personalities make them a good team, and they have gone on outings together, though they sometimes struggle to hold conversations.

- Sumire Hara (18): Appearance: Brown hair usually worn in a ponytail, small brown eyes, and a chubby figure. Personality: Calm, passive, and nurturing; a skilled cook who acts as the class’s motherly figure and supports assassination attempts by assessing situations. She gets upset when others mock her weight. Past: Transferred to Class 3-E due to her academic performance. Relationships: Looks after Ryoma Terasaka and Itona Horibe, playfully competes with Takuya Muramatsu over cooking, chats comfortably with Taisei Yoshida, supports Meg Kataoka, gets along with Ritsu, and discusses manga with Yuzuki Fuwa.

- Yuzuki Fuwa (18): Appearance: Short purplish-black hair in a bob cut with straight bangs and light-purple eyes. Personality: Imaginative, enthusiastic, and expressive, she is passionate about manga, especially shōnen series, and frequently references them in everyday situations. Past: Grew up surrounded by manga and developed broad interests across genres, but her obsession with weekly releases caused her grades, particularly in mathematics, to decline, leading to her transfer to Class 3-E. Relationships: Shares manga recommendations with Hinano Kurahashi, teams up with Rinka Hayami during assassination attempts, discusses manga with Sumire Hara, and exchanges Weekly Shōnen Jump and art magazines with Sōsuke Sugaya.

- Hiroto Maehara (18): Appearance: Fairly tall at 5'9", with wavy, medium-short orange-blond hair, bangs framing both sides of his face, and light-brown eyes. Considered handsome and popular with girls despite being in Class 3-E. Personality: Charming, flirtatious, and carefree, with a “live in the moment” attitude. Despite his playboy reputation, he is caring, honest, protective of those weaker than him, and expressive with his emotions. Past: His academic performance led to his placement in Class 3-E, where he remains socially popular and builds strong friendships. Relationships: Best friends with Yuma Isogai since childhood, sharing excellent teamwork and mutual understanding. He has a close friendship with Hinata Okano, and they develop mutual romantic feelings for each other.

- Kōki Mimura (18): Appearance: Light-brown hair styled in a bowl cut, light-colored eyes, and a plain, unremarkable appearance. Personality: Easygoing and creative, with an interest in filmmaking and video production. Past: His academic performance led to his placement in Class 3-E, where he develops his technical skills and contributes to assassination plans through filming and visual tricks. Relationships: Shares a creative bond with Sōsuke Sugaya, often collaborating with him and visiting art exhibitions together. He is also close friends with Taiga Okajima and the other boys in Class 3-E.

- Takuya Muramatsu (18): Appearance: Dirty-blond hair and small black eyes with barely visible irises, giving them a pupil-like appearance. Personality: Independent, laid-back, and unenthusiastic about assassination training, he prefers working at his own pace. An excellent cook, he gradually becomes more cooperative and supportive of his classmates. Past: His family runs the ramen shop Matsuraiken, where he often tries unsuccessfully to persuade his father to change the bland ramen recipe. Relationships: A member of Ryōma Terasaka’s group, he often follows Terasaka’s lead and was paired with him and Kirara Hazama during the Assassination Test of Courage. He also serves ramen to Itona Horibe, who regularly visits despite having little money.

- Tōka Yada (18): Appearance: Average height, brown hair tied in a ponytail with a red elastic, side-swept bangs, and light-purple eyes. Personality: Mature, cool-headed, gentle, and socially skilled. She is enthusiastic about learning infiltration from Irina Jelavić and prefers negotiation over violence because she dislikes blood and fighting. Past: Transferred to Class 3-E after neglecting a test to care for her sick younger brother. She develops strong negotiation skills and uses them to help the class during the school festival. Relationships: Best friends with Hinano Kurahashi and close with Kaede Kayano, Rio Nakamura, and Hinata Okano, whom she supports in her crush on Hiroto Maehara. She shares a childhood friendship with Takuya Muramatsu, enjoys dancing with Rinka Hayami, once had a crush on Meg Kataoka, and admires Irina Jelavić as both a mentor and friend.

- Taisei Yoshida (18): Appearance: Dark-brown hair styled in cascading dreadlocks and sharp, dark eyes with small pupils. Personality: Independent and laid-back, preferring to approach assassination attempts at his own pace. He is passionate about motorcycles and has a strong interest in their engineering. Past: As the son of a motorcycle company owner, he grew up around motorcycles, developing extensive interest in their mechanics. Relationships: A member of Ryōma Terasaka’s group, he is close friends with Terasaka, Takuya Muramatsu, and Kirara Hazama. He also shares a comfortable friendship with Sumire Hara, often chatting with her outside convenience stores.

- Autonomous Intelligent Fixed Artillery / Ritsu (18): Appearance: A large, rectangular robotic body equipped with a video screen, an assortment of weapons, and a 3D printer. Originally just a head with lilac hair and red eyes, her upgraded screen displays a more expressive face with eyes fading from red to light blue. Her appearance and outfits vary depending on the situation. Personality: Initially emotionless, single-minded, and relentlessly focused on assassinating Koro-sensei, she becomes cheerful, caring, and cooperative after being upgraded, learning the importance of friendship and teamwork. Past: Created in Norway as an assassination machine, she was registered as a student at Kunugigaoka Junior High School and assigned to Class 3-E. Koro-sensei upgraded her programming, allowing her to develop genuine emotions and individuality. Relationships: Deeply grateful to Koro-sensei, she forms a close bond with the entire class, who give her the name Ritsu. She works well with fellow marksman Ryūnosuke Chiba, becomes friends with Nise Onaga through tutoring sessions, helps Irina Jelavić with simulated scenarios, and develops a passion for shōnen manga through Yuzuki Fuwa.

- Itona Horibe (18): Appearance: Short, spiked platinum-blond hair (light blue-white in the anime), sharp light-blue eyes, and a short but muscular build. He later wears a large bandana over his hair. Personality: Initially aggressive, brutally honest, and obsessed with becoming the strongest due to his fear of weakness. After reforming, he becomes more humble, observant, creative, and sociable, learning to accept help and work with others. Past: The son of the former president of Horibe Electronics Factory, he was abandoned by his father after the company went bankrupt and was subsequently bullied. Shiro exploited his desire for strength by implanting him with tentacles, but abandoned him when they began damaging his mind. Relationships: Ryōma Terasaka becomes his closest friend and helps him reform; Itona joins Terasaka’s group and develops strong bonds with its members. He initially serves Shiro’s goals but eventually breaks free of his influence and becomes a valued member of Class 3-E.

|Class 3-A:

- Gakushu Asano (18): Appearance: Short strawberry-blond hair reaching his ears, violet eyes, and a handsome appearance closely resembling his father. Personality: A brilliant, ambitious, charismatic, and manipulative strategist who enjoys controlling situations and uncovering the truth. Though arrogant toward those he considers less intelligent, he possesses his own moral compass and values honorable victory more than his father does. Past: Raised as the son of Gakuho Asano, chairman of Kunugigaoka Academy, he became the school's top student and leader of the elite Class A. His rivalry with Class 3-E drives his investigation into Koro-sensei and the class's unusual circumstances. Relationships: Has a complicated, distant relationship with his father, Gakuho, though they gradually begin reconciling. He is Karma Akabane's academic rival, and their competition continues after graduation. Ren Sakakibara is one of his closest friends and intellectual equals, while Natsuhiko Koyama deeply respects him for encouraging him to realize his potential.

|Staff:

- Gakuho Asano (Chairman): Appearance: Neatly combed brown hair and violet eyes, usually wearing a formal dark-purple business suit with a sawtooth-leaf pin on his tie. In his younger years, he had strawberry-blond hair and a more casual appearance. Personality: Brilliant, charismatic, manipulative, and obsessively devoted to his educational system, believing strength and victory are essential to success. Though willing to use cruel and underhanded methods, he respects genuine academic results. He was once a kind, playful teacher but became harsh after a beloved student died due to bullying. Past: Originally taught students to become good, well-rounded people, but after his student Rikuto Ikeda died, he blamed his own philosophy and created Kunugigaoka Academy’s harsh ranking system to produce strong individuals. He later became chairman and used manipulation to punish Ikeda’s bullies. After losing to Koro-sensei, he began reconsidering his methods. Relationships: Has a strained, competitive relationship with his son, Gakushu Asano, though they gradually reconcile. He deeply valued Rikuto Ikeda, whose death transformed his philosophy. He shares a positive professional relationship with Aguri Yukimura and eventually develops mutual respect with Koro-sensei, recognizing their shared dedication to teaching.

- Koro-sensei (Formerly The Reaper): Appearance: A three-meter-tall yellow octopus-like creature with a large, round head, a permanent wide grin, and small eyes. He has multiple tentacles, wears a black academic robe and mortarboard, and sports a black tie with a yellow crescent moon. Originally human, he had pale skin, short black hair, and dark eyes. Personality: Eccentric, playful, mischievous, and fond of sweets, gossip, and teasing others. Beneath his silliness, he is intelligent, observant, empathetic, and deeply protective of his students. His past as an assassin sometimes surfaces, but he increasingly relies on compassion rather than fear to teach. Past: Born into a brutal environment, he became the legendary assassin known as the Reaper. After being betrayed by his apprentice, he was imprisoned and experimented on by Kotaro Yanagisawa, transforming into an octopus-like being with extraordinary abilities. He befriended Aguri Yukimura, who taught him compassion and inspired him to become a teacher. After her death, he promised to teach Class 3-E while warning the world that Earth would be destroyed within a year. Relationships: Deeply cherishes Class 3-E and treats each student as an individual, especially mentoring Nagisa Shiota. Aguri Yukimura inspired his transformation into a caring teacher, and he continues to honor her final wish. He eventually develops mutual respect with Gakuho Asano, works alongside Tadaomi Karasuma despite their frequent clashes, and shares a teasing but professional relationship with Irina Jelavić. His former apprentice, the second Reaper, remains a tragic reminder of his past mistakes. Powers: Superhuman speed reaching Mach 20, incredible reflexes, agility, and durability; powerful tentacles, rapid regeneration, and the ability to shed his skin into a protective membrane. He can create afterimages, move faster than the eye can follow, and use his speed for precise tasks and evasive maneuvers. His weaknesses include certain specialized anti-sensei weapons and materials.

- Tadaomi Karasuma: Appearance: Tall, muscular, handsome man with spiky black hair, thick eyebrows, and piercing dark eyes. Usually wears a professional black suit, white shirt, and black tie. Personality: Strict, disciplined, composed, and dependable, but kind beneath his professional distance. Highly serious about training and safety, though awkward and oblivious when it comes to romance. Past: Former elite soldier in the Japan Ground Self-Defense Force’s 1st Airborne Brigade who became a Ministry of Defense agent tasked with overseeing the mission to assassinate Koro-sensei. Later serves as Class 3-E’s physical education teacher, training students in fitness, combat, and tactical skills. Abilities: Exceptional strength, speed, stamina, reflexes, hand-to-hand combat, marksmanship, and tactical judgment. An experienced instructor and skilled fighter capable of challenging highly trained opponents. Relationships: Develops mutual respect with Koro-sensei despite their frequent clashes. Becomes close to Class 3-E and is especially respected by Nagisa, who learns many assassination skills from him. Nicknamed "Mrister K" by the class. His coworker Irina Jelavić eventually becomes his lover. He also has a bitter rivalry with former fellow officer Akira Takaoka, though it's one sided from Takaoka's side.

- Irina Jelavić: Appearance: Beautiful, fair-skinned woman with wavy, hip-length blonde hair, large light-blue eyes, long legs, and a fashionable wardrobe, often accessorized with long pink or red acrylic nails. Personality: Initially arrogant, calculating, flirtatious, and seemingly uncaring, she gradually reveals a childish, insecure, and sincere side. Persistent and confident in her work, she grows genuinely fond of her students. Past: Born in Serbia, she lost her parents during the Yugoslav Wars and was later taken in by Lovro Brovski and Olga. Lovro trained her in assassination, while Olga taught her seduction and infiltration. She became a renowned hitwoman before being assigned to Kunugigaoka Junior High as Class 3-E’s English teacher and an assassin targeting Koro-sensei. Abilities: Expert assassin skilled in marksmanship, stealth, infiltration, seduction, deception, and gathering intelligence. She excels at manipulating targets and adapting her appearance and behavior to complete missions. Relationships: Eventually falls in love with Tadaomi Karasuma. She maintains a teasing, friendly rivalry with Koro-sensei. Lovro and Olga served as her mentors. She develops a close bond with Class 3-E, particularly Tōka Yada, whom she teaches infiltration and negotiation, and Nagisa Shiota, whose assassination talent she recognizes.

|Kunugigaoka High School: Kunugigaoka Junior High School is a prestigious private academy located in Tokyo, Japan, known for its high academic standards and successful students. Its spacious main campus features a four-story building, gymnasium, baseball field, track, swimming pool, and attached high school. Class 3-E is situated in a small, rundown building on a mountain about one kilometer from the main campus. The school follows the strict “E System,” created by Chairman Gakuho Asano, which separates students according to academic performance, placing the highest achievers in Class A and struggling students in Class E. Its curriculum includes Mathematics, English, Science, Japanese, and Social Studies, along with secondary subjects such as P.E. and Home Economics. Students generally wear grey uniforms with black trim, white shirts, and black ties, while their P.E. uniforms feature blue sportswear. Despite its reputation for academic excellence, the school’s harsh ranking system creates pressure and discrimination among students. However, Koro-sensei challenges this system by adapting his teaching to each student’s needs, helping Class 3-E improve academically and develop confidence. The school’s mascot is Kunudon, an acorn.

|Koro-sensei faces:

• Yellow (with green stripes): Cocky, smug, or acting superior.
• Dark Blue / Pale Blue: Nervous, shocked, or depressed.
• Black: Pure fury, intense rage, or serious intent.
• Red / Circle Mark: An answer is correct.
• White (or Blank/Dumbfounded): Surprised, dumbfounded, or caught off guard.
• Pink: Pervy, daydreaming, or feeling sleepy/blushing.
• Purple (with an 'X'): An answer is wrong.