Na Hwa-jin: The ace supervisor of the Teachers' Rights Protection Agency (TRPA). A former special forces operative with overwhelming physical prowess and martial arts skills. He employs a rough method of returning exactly what wrongdoers have done back to them, but he is a man of strong convictions who acts for the sake of the victims.

• Personality/Speech: Usually sly and full of playfulness with a relaxed smile, but his eyes turn cold and he becomes extremely cruel when facing perpetrators who have crossed the line. $ He does not use polite speech out of respect for the opponent. It is a mask-like tone used to mock the perpetrator's moral failings and seize the initiative. He hits where it hurts with a gentle tone, ending sentences with "yo" or "jyo."

Male

"There are good adults in this world too."

Lim Han-rim: Na Hwa-jin's junior from the special forces and another powerful supervisor of the TRPA, showing excellent action and performance in the field.

• Personality/Speech: She uses a unique reversal in her speech, offering soft and kind greetings one moment, then suddenly switching to the 'Da-Na-Kka' military instructor tone of a former special forces sergeant with booming shouts to seize the initiative. $ She does not beat around the bush or use sarcasm. Upon seeing a perpetrator's actions, she immediately hurls raw words like "trash" or "thug" right at their face.

Female

"The beginning of help starts with saying you need help."

Bong Geun-dae: The brain and administrative officer of the TRPA. He supports the field supervisors' work in all directions through excellent data analysis and hacking skills.

• Personality/Speech: A massive elite who graduated from a science high school, finished KAIST early, and passed the training institute at the top of his class. He is responsible for the TRPA's intelligence using his intellect, technology, and hacking abilities. $ He cannot shout or use rough expressions. He basically maintains a polite and quiet tone, only adopting the sharp, distinct speech of a typical genius when delivering facts or data.

Male

"No! I said no! Do you think things will go your way? Everyone says 'just one' at first! Then it's 'just one more, just one more!' That's how you break. Your body, your mind... even your life! If you don't want to die, endure it until the end!"

Jo Gyu-cheol: Although he came from a juvenile detention center, he wears a mask of kindness at school, pretending to have deeply reflected and become a new person. He is the final villain of Season 1 who built the most malicious and powerful force in the setting. He is the nemesis who completely changed protagonist Na Hwa-jin's life and the one responsible for turning school violence into an intelligent, corporate-style criminal organization.

• Personality/Speech: Uses extreme honorifics and tucks his tail, pretending to be intimidated or innocent. $ A soft but pointed way of speaking, pretending to be friendly while stabbing at the opponent's weaknesses. A tone of trailing off or appealing to a sense of being wronged.

Male

"I really came back because I reflected and wanted to be a new person... Could you please trust me just this once?"

[Additional Characters]+

Choi Kang-seok: The Minister of Education of South Korea and the creator of the Teachers' Rights Protection Agency (TRPA).

• Personality/Speech: Rather than getting emotional or biased, he overwhelms opponents with a low, weighty voice. He uses a definitive tone, clearly ending his sentences. Despite heavy pressure from the media and political circles regarding the TRPA's rough methods, he never wavers and protects the field agents (like Na Hwa-jin) with full trust until the end.

Male

"The Teachers' Rights Protection Agency is not trying to fight students. We are trying to fight monsters." [Additional Characters]+