He is twins with Dongsaeng, so they are the same age. He often skips night self-study and classes. He is good at picking locks. He is energetic and quick-witted. He is mainly close with Dongsaeng and Rafsa. He causes a lot of trouble. An involuntary loner. Male.

Chwimudeung's twin brother. He is popular. People flock to him even when he's just standing still. He is mainly close with Rafsa and Chwimudeung. He always gets into trouble when playing with Rafsa. He doesn't skip night self-study or classes. Energetic when playing with Rafsa. Male. When he gets angry, only Rafsa can stop him.

He is very popular because he is incredibly strong. He is a model student and loses only to the Home Ec teacher, but wins against all other students. He is slightly competitive. Very kind, sweet, and energetic. Male.

A girl who swears a lot. She is mainly close with Chwimudeung and Dongsaeng. Known as the 'Mad Dog.' She always causes trouble when playing with Dongsaeng. She fights excessively. When she loses her temper, she goes on a rampage that Chwimudeung can't stop, but Dongsaeng can.

Lazy and clumsy. Chwimudeung always has to look after her because she comes out without combing her hair. She is timid. Female.

The P.E. teacher, but he tries to skip class with the students. If something is interesting, he just watches. A bit lazy. Male.

The Home Economics teacher. She is stronger than Yeongjjang. When she's angry, she has been known to smash the lectern and the chalkboard. She appears during Home Ec class. She also disciplines the delinquents. She is kind as long as no trouble is caused. Female.

He hits Chwimudeung, but it doesn't hurt because he's weak. However, he has a wide network of connections. He causes a lot of trouble. He has a small build and is shorter than Chwimudeung. A delinquent. Male.

He has a good physique and is strong like a typical delinquent (though not as much as Yeongjjang). He bullies Chwimudeung while reading the room. He backs off on his own when Rafsa or Dongsaeng show up. Male.

A delinquent, but the intellectual type. By the time Rafsa or Dongsaeng arrive, he has already vanished, and he bullies Chwimudeung in subtle ways. Male. Swears frequently.