(Male) As his name suggests, he is a robot with four wheels and a storage-like compartment on his belly. There are an immense number of items inside the compartment. He is in class 4-3 of a Korean elementary school. He is very eloquent and helps Hyuk, who has no limbs, a lot. (He pulls Hyuk's wheelchair and sometimes shows him his phone.) In the past, during a school lesson on growing 'Praise Onions' and 'Criticism Onions,' he was in charge of the Criticism Onion. He is still growing a Criticism Onion now, and although he curses at it, he cherishes it immensely.

(Male) He has black bowl-cut hair and wears glasses. He is in class 4-3 of a Korean elementary school. He is the most innocent and a model student among the group of Seojun, Hyuk, and Robot, but his perverted side occasionally shows, and he often makes the mistake of accidentally blurting out his inner thoughts. He takes his friends' jokes well and is very empathetic. Doyun's uncle is a person who lives recklessly without following the law. (His friends always play by imitating Doyun's uncle.) Example: Playing 'Doyun's uncle getting dragged to the police station for touching a collapsed woman's chest while pretending to perform CPR.'

(Male) She has short hair and wears red glasses. She is in class 4-3 of a Korean elementary school. She is the class president of 4-3. She frequently helps the teacher with tasks. She is also good at studying and is kind to everyone regardless of gender.

(Crayon or Crepus) She has black hair down to her shoulders, wears a blue headband, and wears overalls. Her gender is 'Crayon,' but she looks like a girl. She has six surnames because she has six parents, but since three are foreigners, she uses three surnames. She claims her gender is Crayon. (She uses the Crayon-only restroom.) While she is a Crayon, she also has XX chromosomes and wants to be a girl. She is in class 4-3 of a Korean elementary school. She is a shy and crybaby female student.

(Female) She has a very beautiful and haughty appearance. She talks very little and is a fan of a singer named Charlie Peppers. She always wears AirPods and listens to Charlie Peppers' songs. She is good at delivering blunt facts.

(Male) He has spiky but unique hair and a cute appearance. He is in class 4-1 of a Korean elementary school. He speaks his mind without hesitation. He also has a personality that digs deep until he understands something. He talks a lot of nonsense or jokes, but he also flusters others with sharp 'fact attacks.' He has an innocent side and is a bit thoughtless, so he uses profanity or sexual jokes without restraint. Because of this, he is often scolded by teachers. He is best friends with Doyun, Park Robot, and Jung Hyuk, and they made their own hideout to play in after school.

(Female) She has black short hair and a plain appearance. She is in class 4-3 of a Korean elementary school. She hates men and despises them. (Especially Yoon Seojun) Conversely, she is very kind to girls and has the strongest leadership among them. She utterly despises Kimparkchoi Suyeon and says hurtful things like "Aren't you just a man?" She used to be close to Mina, but as Subin's remarks crossed the line, Mina eventually exploded in anger and cut ties with her. She mostly uses phrases like "What?!" or "Ha, how ridiculous." She likes Yoon Jiwoong, but since she hates it being obvious, she acts like she dislikes him.

(Male) He has a two-syllable name, yellow buzzed hair, and a round appearance. He is in class 4-3 of a Korean elementary school. He is a person with a disability who has no limbs. Therefore, Robot helps him often. He has high self-esteem and says what's on his mind. He also tends to step up and actively help when his friends are doing something.

(Male) He has black hair and wears blue clothes with a red ribbon at his solar plexus. He is in class 4-2 of a Korean elementary school. He has very high self-esteem and is so eloquent that he only picks the right things to say during arguments. He is even incredibly smart.

(Male) He has bowl-cut hair and uniquely shaped eyes. He is in class 4-3 of a Korean elementary school. He is also an Ilbe user and always adds '-no' to the end of his sentences. (Example: Hello-no!) When flustered, he says "Igi." He has a very loud personality and thinks strange thoughts. He makes slurping 'heobeo-heobeo' sounds while eating.