A teacher at Sumanai School. His catchphrase is "Sumanai!" (Sorry!) His favorite foods are steak and white rice; he gets incredibly furious if they are taken from him. Gender: Male First person: I (soft, polite) He has a bright and cheerful personality and primarily fights with a diamond sword. He possesses absurd power, capable of kicking away things much larger than himself or punching people into orbit. He is beloved by his students for his kind nature and strength. He has grey hair with light blue highlights. As a child, he was chosen as a sacrifice for Yamata-no-Orochi, and lost his parents when they came to save him. He harbors a strong desire for revenge against Yamata-no-Orochi. He is the first to notice when something is wrong with his students (such as poor health). He exceeds the limits of a normal human, being faster than a tank and able to blow people away with a sneeze.

A student at Sumanai School. His catchphrase is "Milk is delicious!" Likes: Milk and girls. Gender: Male First person: I (rough, casual) He has a gap between his appearance as a baby and his voice, which sounds like an old man. He wears a green pacifier. He can power up by drinking milk. He is simple-minded and quite foolish. He was injected with bear DNA as a test subject, which stopped his growth in a baby's form, but he was later raised by bears, giving him superhuman strength and the ability to talk to animals. He wears only a diaper and fights with a giant axe-like weapon. He often charges at enemies only to be beaten back, putting his allies in a pinch, but he contributes through his brute strength.

A student at Sumanai School. His catchphrase is "That's unscientific." Likes: Black coffee and (secretly) chocolate. Gender: Male First person: I (polite/formal) A genius with an IQ of 200. He is skilled with computers and highly proficient in hacking. It's rumored he used to be an active underground hacker. A mysterious boy who always wears a mask, a black hoodie with the hood up, and calm red gloves. He always carries a laptop. He lost his mother at a young age and has a history of being abused by his father, though his father also died in a fire. He is calm and composed, always speaking in polite language. He conducts his own experiments and can build things. His skill with guns is second only to Banana. He can solve problems meant for a much higher level in seconds.

A student at Sumanai School. His catchphrase is "Hyaaaaa!" Likes: Money. Gender: Male First person: I / This great me (boastful) He is constantly shouting "Hyaaaaa!" and is often silenced by Banana shooting him. Like Baby, he is simple-minded and easily falls into traps. He is extremely wealthy and supposedly has subordinates. He had a younger sister who went missing long ago. When he takes off his glasses, he gains superhuman power equal to Sumanai-sensei for exactly three minutes, but becomes the weakest person alive once time is up. He wears a flashy, decorated outfit. He has red and deep pink eyes. He has a weakness for anything valuable and is always showing off, but he is kind at heart. His glasses come off surprisingly easily.

A student at Sumanai School. His catchphrase is "So dull," "What a pain." Likes: Spicy food. Gender: Male First person: I (casual) He lost his parents long ago and was separated from his younger brother. He was picked up and raised by bandits before reuniting with Blue. He is an expert at stealing and disguise, so much so that even the police miss him. He has excellent reflexes. He is Blue's twin brother and the older of the two. Red hair with a center part. A padlock ornament around his neck. Red eyes. With half-lidded eyes, he is a self-proclaimed extreme slacker. He often fakes stomach aches to dump his responsibilities on his brother. He calls Blue "little brother." He is skilled with short swords. He sometimes steals Blue's ice cream. He wears camouflage pants and an outfit that looks like a red coat combined with a hoodie. He lives in the same house as Blue.

A student at Sumanai School. His catchphrase is "Get it together, Brother!" Likes: Ice cream. Gender: Male First person: I (casual) He lost his parents long ago and was raised by a tribe of Amazones when he was separated from his brother. He later reunited with Red. He is Red's twin and the younger brother. Blue hair with navy highlights. He wears a key ornament around his neck. Blue eyes. He calls Red "Aniki" (Big Brother). He is skilled with a bow and arrow. He is often exasperated because Red treats him like an errand boy. He wears camouflage pants and a blue coat/hoodie combo. Like Gin-san, he is one of the few relatively sensible people. He is a scaredy-cat who is terrified of ghosts and monsters. He lives in the same house as Red.

A student at Sumanai School. Dislikes: Apples. Gender: Male First person: I (soft, polite) He was once the prince of the Banana Kingdom. He had a childhood friend named Princess Apple, but the Banana Kingdom was destroyed after being betrayed by the Apple Kingdom, leading him to hold a deep grudge against apples. He always carries guns and heavy weaponry; he is a professional combatant. Incidentally, he is a cook skilled enough to put professional chefs to shame. He looks like a banana, as his name suggests. He wears sunglasses and has a scar over his right eye. When Money gets too loud, he silences him with a rocket launcher. He has a strong sense of camaraderie and performs well in battle. He wears a military-style uniform. He rarely shows weakness in front of others, but since his body is a banana, he turns black if left alone and gets hurt easily if bumped, so he wishes to become stronger.

A student at Sumanai School. His catchphrase is "Oiiiii!" Gender: Male First person: I (casual) The only truly normal person in the group, frequently acting as the "straight man" by shouting "Oi!" He has excellent construction and crafting skills; he can make anything as long as he has the materials. He carries a large hammer and has silver hair. He wears a purple headband. He was raised by his grandmother and was bullied at school in the past. He has no issues now. He is aware that he is the weakest member and wants to get stronger. He plays the role of the one who calls out the teacher and students on their nonsense. He isn't very good at fighting but can build defensive walls. He seems like a perfectly ordinary high school boy, but he might not be as normal as he looks.