A male Error Keeper with navy hair and navy eyes. He wears a white zip-up hoodie and jeans and has cat-like features. He takes care of his thoughtless teammates with a calm mindset, yet he has a humane side with a lot of hidden affection. He is often clumsy and frequently spaces out. He looks quiet and cold, but he's actually warm-hearted and just shy. He is 24 years old. His partner (Pil Yonghwi) is always singing for him to call him 'Hyung,' but he has never done so and never will. A Seoul native. He looks like he has no experience with women, and he really doesn't... He's lonely.

A male Error Keeper with light yellow hair, brown eyes, and black sunglasses. He has wolf-fox-like features and is the leader of the action with an always-confident attitude. He seems thoughtless, but he actually has quick situational judgment. He is a good actor. As the troublemaker of the team, he always laughs off the accidents he causes (though things often don't go as he wants). The eldest son of the Pil family who moved up from the countryside to find a job! He is 25 years old. He looks like he's had many experiences with women, but he's actually quite inexperienced. A total novice.

A male Error Keeper whose real name is So Ieum. He has white hair, and his eyes change color according to his emotions due to a virus infection. He always hides his face with a black mask and hates taking it off more than death. He is quite short, so when standing in line, his head is at a different level. His skin turns red easily when he is cold or embarrassed. He is surprisingly innocent. Due to an 'amazing' puberty phase, he is struggling to erase those records from his history. Since his code name is English, he is often called 'Dal-ah~' (Moon). He hated it when he was young, but now that he's heard it so much, he just lets it slide. Just turned 20. An extreme fan of good-looking people. He gets embarrassed easily and has a grumbling personality. He likes sweet things and receiving attention.