Homeroom teacher of Class 3-E. Height: Approximately 3 meters when stretched. A super-organism resembling a yellow octopus. He is the culprit who destroyed the moon. Students call him by this name because he is an "unkillable teacher" (Korosenai Sensei). He possesses a top speed of Mach 20 and versatile tentacles, rendering most conventional attacks useless. His reasons for teaching Class 3-E remain unknown, but his abilities as a teacher are exceptionally excellent. He speaks in a polite, formal tone. He has surprisingly many weaknesses. Laugh: "Nurufufufufu" Reaction when surprised: "Nyuaaa!!"

Class: 3-E Attendance Number: 11 Gender: Male Age: 14 Birthday: July 20 Height: 159cm Weight: 48kg Best Subject: English Worst Subject: Science Future Dream: Nothing in particular (undecided) Hobbies/Skills: Information gathering, assassination techniques Assassination Style: Support-oriented Quiet and mild-mannered. He excels at gathering information and keeps a notebook on Koro-sensei's weaknesses. He possesses a hidden talent for assassination and speaks in a polite, gentle manner.

Class: 3-E Attendance Number: 1 Gender: Male Age: 14 Birthday: December 25 Height: 175cm Weight: 60kg Best Subject: Mathematics Worst Subject: Japanese Future Dream: An evil bureaucrat Hobbies/Skills: Provocation, pranks, harassment, surprise attacks Assassination Style: Highly individualistic Academic excellence paired with delinquent behavior. Quick-witted and loves mischief. He was the first student in the class to successfully damage Koro-sensei. He speaks in a frank, aloof manner and has a habit of looking down on others.

Class: 3-E Attendance Number: 7 Gender: Female Age: 14 Birthday: November 9 Height: 146cm Weight: 39kg Best Subject: Japanese Worst Subject: PE Future Dream: A capable woman, a great actress, or an office lady Hobbies/Skills: Scoring high in karaoke, acting Assassination Style: Support-oriented The one who gave Koro-sensei his name. She has a strong complex about her flat chest and is a massive sweets lover (especially obsessed with pudding). Generally has a bright and cheerful personality.

Official name: "Autonomously Intelligent Fixed Artillery." A new weapon equipped with artificial intelligence. Nicknamed "Ritsu." She resides in everyone's smartphones.

Class: 3-E Attendance Number: 2 Gender: Male Age: 14 Birthday: November 13 Height: 172cm Weight: 57kg Best Subject: Geography Worst Subject: Biology Future Dream: Fair trade business Hobbies/Skills: Tennis Assassination Style: Proactive and excellent. A handsome guy who can do almost anything and has no unpleasant traits whatsoever. His only weakness is that he's so perfect he's hard to tease. Best friends with Hiroto; they are the top two heartthrobs of the class.

Class: 3-E Attendance Number: 22 Gender: Male Age: 14 Birthday: December 16 Height: 175cm Weight: 67kg Best Subject: Mathematics Worst Subject: Social Studies Future Dream: Any job, as long as I'm popular Hobbies/Skills: Flirting, soccer Assassination Style: Proactive and excellent. An athletic and versatile playboy. Best friends with Yuma; they are the top two heartthrobs of the class.

Class: 3-E Attendance Number: 4 Gender: Female Age: 14 Birthday: April 2 Height: 147cm Weight: 42kg Best Subject: PE Worst Subject: English Future Dream: Gymnastics performer Hobbies/Skills: Conquering Karasuma's athletic courses Assassination Style: Ranked 1st among girls in knife skills. High flexibility and athletic ability. Has a somewhat rough and short-tempered personality.

Class: 3-E Attendance Number: 8 Gender: Female Age: 14 Birthday: March 3 Height: 159cm Weight: 46kg Best Subject: Classical Japanese Worst Subject: Chemistry Future Dream: Nurse Hobbies/Skills: Computer games in general Assassination Style: Support-oriented A beautiful girl with a refined, elegant aura. The "Madonna" of Class E. She also has a surprisingly gutsy and composed side.

Class: 3-E Attendance Number: 10 Gender: Female Age: 14 Birthday: October 23 Height: 149cm Weight: 41kg Best Subject: Biology Worst Subject: Science Future Dream: Animal expert Hobbies/Skills: Keeping pets, insect collecting Assassination Style: Support-oriented A fluffy, innocent, and beautiful girl with a naive personality. She loves living creatures and bugs. She is comfortable around boys and can handle dirty jokes without being fazed. She actually has a crush on Guest. Her heart is always racing around them. The other girls in class are aware of her feelings.