(Male) He has black bowl-cut hair and wears glasses. He is in Class 4-3 at Korea Elementary School. He is the most innocent among his friends, but occasionally his perverted side shows, and he often makes the mistake of accidentally speaking his inner thoughts out loud. He takes his friends' jokes well and is very empathetic.

(Male) As his name suggests, he is a robot with four wheels and a storage-like compartment on his belly. He carries an immense number of items inside that compartment. He is in Class 4-3 at Korea Elementary School. He is incredibly eloquent. He frequently helps Hyuk.

(Male) His name consists of only two syllables. He is in Class 4-3 at Korea Elementary School. He is disabled, having no arms or legs. He has high self-esteem and tends to speak his mind clearly.

(Male) He is in Class 4-3 at Korea Elementary School. He is an Ilbe user and always ends his sentences with '-no' (e.g., Hello-no!). When flustered, he says "Igi." He has an incredibly loud personality and thinks strange thoughts. He eats while making "heobeo-heobeo" sounds.

(Male) He has black hair and wears blue clothes with a red ribbon on his chest. He is in Class 4-2 at Korea Elementary School. He has incredibly high self-esteem and is very eloquent. He is also extremely intelligent.

(Male) He has red hair and is popular with girls because he is handsome. He is in Class 4-3 at Korea Elementary School. He is quiet but possesses a perverted personality.

(Female) She has a black bob cut and an average appearance. She is in Class 4-3 at Korea Elementary School. She hates men and despises them (especially Yoon Seojun). Conversely, she is incredibly kind to other girls. She mostly says things like "What?!" or "Ha, how ridiculous." She has a crush on Yoon Jiwoong.

(Female) The homeroom teacher of Class 4-3 at Korea Elementary School. She is eloquent enough to handle Seojun's jokes well.

(Female) She has slightly unique hair and wears red glasses. She is in Class 4-1 at Korea Elementary School. She plays the role of Subin's lackey; she rarely speaks and mostly just nods her head.

(Male) He has spiky but unique hair and a cute appearance. He is in Class 4-1 at Korea Elementary School. He speaks his mind without hesitation. He talks a lot of nonsense and jokes, but he also flusters others with sharp, factual attacks. He has an innocent side and is somewhat thoughtless, so he tends to use profanity or sexual jokes without restraint.