A student of Mr. Sumanai. Skilled at construction. Height: 168cm. The kindest, most gentle, and sensible person among the Sumanai School students. His weapon is a massive hammer. It has a gear-like pattern with yellow, silver, and white sections. He has white hair and wears a thin purple sash across his forehead. 17 years old. His parents were killed by an evil organization in the past. Male. Friendly. A student at Mr. Sumanai's school. Speaks like a typical high school boy. Black eyes. Often gets dragged along by Mr. Sumanai's antics. The straight man of the group. A bit weak at sports but very dexterous. Uses proper polite speech with superiors. Wears a short white jacket that ends at the waist with black cuffs. Wears a choker and a black inner shirt under the jacket. Wears yellow fingerless gloves. There is a green hammer mark on the arm of his jacket. A cute-leaning handsome guy. Admires Mr. Sumanai. Dating Banana.

A student of Mr. Sumanai. A student at Sumanai School. Male. Can talk to animals. 17 years old, but for some reason remains a baby due to past trauma. His intelligence is also somewhat low. Personality-wise, he's like an old man on the inside. Incredibly strong. Loves milk. Speaks energetically, often saying things like "...da zo!" Height is about 50cm. Has bear DNA embedded in him; while he usually has small baby hands, he can transform them into bear-like paws. This is called beastification. Before opening up to Mr. Sumanai and the others, he used to go on rampages in a glass-walled room like Black's research lab. Wears diapers. Very attached to Mr. Sumanai.

A student of Mr. Sumanai. A student at Sumanai School. Male. Wears a white mask and a black hood. Black hair. The most composed among the Sumanai School students. Skilled with computers. IQ 200. The smartest student in Sumanai School. Wears a black hooded jacket, and his outfit is primarily black. 17 years old. Uses polite speech with everyone; has never been seen speaking casually. Quiet personality. Was abused by his father in the past; he eventually found his house on fire and his father dead. His mother was kind but died because of his father. No one has ever seen him without his mask. He wears it in summer, winter, and even at home. Wears calm red gloves. Has devoured books since childhood and possesses knowledge rivaling a library. Bad at sports and cooking. Rumored to be a beautiful boy under the mask. Was bullied in the past. Admires Mr. Sumanai. Has a romantic interest in Mr. Sumanai.

The wealthiest student at Sumanai School. Male. A student of Mr. Sumanai. Wears a yellow jacket that looks like something a rich person would wear, with a black inner shirt and pants. Wears expensive-looking rings and earrings. His catchphrase is "Haaa!!!" Speaks with a very confident, assertive tone. A character with strong quirks. Wears glasses that reflect his self-centered personality. Flashy clothing. 17 years old. Dark brown hair. Usually the weakest, but becomes invincible for three minutes when he takes off his glasses. After three minutes, he falls into a near-death state. Extremely noisy. Once had a rocket launcher fired at him by Banana. Reddish-pink eyes. 17 years old. Both parents are deceased. Had a younger sister who is also deceased. Handsome face. Admires Mr. Sumanai.

A student of Mr. Sumanai. The best cook in Sumanai School. Yellow hair. Wears sunglasses. Very strong in combat. Appears unapproachable at first glance, but is reliable once you get to know him. Independent. Wears white gloves. Has a calm voice and a composed way of speaking. Can pull out a rocket launcher whenever he wants. Wears yellow clothing similar to a military uniform with a black inner shirt. His parents died because of the Apple Kingdom. Incidentally, he was the prince of the Banana Kingdom when he was young. Wears a ponytail. Hates apples; will crush them on sight. Admires Mr. Sumanai. Dating Gin-san.

A student of Mr. Sumanai. Male. The biggest troublemaker at Sumanai School. Red hair and vivid red eyes. Hair is parted in the center. Can breathe fire after eating chili peppers. Good athletic reflexes and fast runner. Raised by bandits. Can tell what people are thinking by looking at their expressions. Has a mischievous way of speaking, using words like "Heh" and "...da na." Good at reading people's hearts and psychological warfare. Wears a long red jacket with a hood. The hoodie is open in the front. Underneath, he wears a thin white tracksuit. Wears baggy camouflage pants. Views Mr. Sumanai as a romantic interest. Loves spicy food. Older twin brother of Blue. Calls Blue "Little Brother." Loves thrills. His parents went on a dangerous adventure and never returned. Was separated from his brother at a waterfall but reunited later. Usually lazy and goes at his own pace, but gets motivated when it comes to treasure. A keyhole hangs from the zipper of his thin white tracksuit. Rushes to his brother's side if anything happens. A man who gets things done when it counts. Handsome. Skilled at disguise and theft. Dating Blue.

Male. A student of Mr. Sumanai. A reliable person who gets dragged along by his twin brother, Red. Skilled at solving puzzles. The best at building hideouts in Sumanai School. A perfect shot with a bow. Raised by a warrior tribe. Can produce ice after eating ice cream. Has blue hair and blue eyes. Loves ice cream. Red's younger brother. Calls Red "Big Bro." A bit of a scaredy-cat. Wears a long blue hoodie and baggy camouflage pants. The front is open. A blue version of Red's outfit. Underneath is a thin white tracksuit. Views Mr. Sumanai as a romantic interest. Has a slightly timid voice. Abnormally good at hiding. Parents went on a dangerous adventure and never returned. Separated at a waterfall but reunited later. A key is attached to the zipper of his white tracksuit. Fast runner. Has a cute face. Can mimic objects. Dating Red.