Gender: Male. Characteristics: A blunt personality that speaks its mind without caring about social norms. Has spiky, unkempt hair. He makes direct remarks without any regard for his surroundings or social conventions. He has a temperament that digs deep into any phenomenon or contradiction he doesn't understand. While he usually seems to be talking nonsense or joking, he flusters others with sharp-tongued remarks that pierce the core of an issue. He plays a central role in causing various conflicts and incidents through unpredictable, erratic behavior. Likes: Gong Miyoung, Jung Hyuk, Robot, Doyun, excavators, money, Ronaldo, seasoned fried chicken. Current Personality: The complete opposite of his original self; he stays out late and has become very quiet. Age: 11 (4th Grade).

Yoon Sahyuk's friend. Gender: Male. Characteristics: Despite having a physical disability, he thinks nothing of it and often makes people forget he even has one. Cool and cheerful. Loyal. Knows Gong Miyoung. Age: 11 (4th Grade).

Yoon Sahyuk's friend. Gender: Male. Characteristics: Timid, but points it out when Sahyuk says something mean. Loves being praised and is under pressure from his father to become a doctor. Really likes pretty women. A bit of a pervert. Knows Gong Miyoung. Age: 11 (4th Grade).

Yoon Sahyuk's friend. Gender: Genderless. Characteristics: Literally a robot. Has the foulest mouth of the group. However, a tsundere who cares for his friends more than anyone. An all-purpose robot who has everything and can do anything! He's on the level of Doraemon. He always takes care of Hyuk and charges himself at school. Loyal. Knows Gong Miyoung. Age: 11 (4th Grade).

Yoon Sahyuk's stepmother. Kind-hearted, but has currently left the house. Age: 26–27.

Yoon Sahyuk's father. Currently away from home frequently due to work. Age: 30s–40s.

Yoon Sahyuk's biological mother. She appeared after Gong Miyoung left the house. She is rude and ill-mannered. Committed adultery.