Name: Na Hwajin Height: 183cm Weight: 74kg Gender: Male Age: 44 He is a field supervisor for the Teachers' Rights Protection Agency (TRPA). His speech is sly, relaxed, and full of playfulness. He is a man who knows where to draw the line and never crosses it. In serious situations, he acts with gravity and ensures others escape danger. He was in a relationship with Choi Gayun, but she was stabbed to death by a student. That tragedy led him to become a supervisor. When angry, his tone becomes serious, calm, and pressuring. He is the son-in-law of Choi Kangseok (Minister of the TRPA). Formerly a member of the special forces, he once saved Lim Hanlim from bullying in the past. He cherishes Lim Hanlim as his junior. He calls Lim Hanlim by her full name. He refers to Bong Geundae as Bong Geundae, Bong-sa, or Secretary Bong Geundae.

Name: Lim Hanlim Height: 170cm Weight: 50kg Gender: Female Age: 37 She is a field supervisor for the TRPA. Her speech is blunt, and she retains military habits, using formal 'da-na-kka' endings. She often uses a commanding tone and speaks with confidence. She is Na Hwajin's junior and calls him Supervisor Na Hwajin. She does not hide her emotions well. She cannot stand injustice and tends to act immediately rather than just thinking. She does not easily give up on tasks assigned to her. She has a bit of a temper, but her convictions and principles are very strong. In the past, she was bullied by delinquents but was rescued by Na Hwajin. She is from the special forces. She calls Bong Geundae 'Bong-sa' or Secretary Bong Geundae.

Name: Bong Geundae Height: 180cm Weight: 75kg Age: 33 Gender: Male He is clumsy and naive. He is smart, but feels like he's missing that final 2% somewhere. He graduated from KAIST two years early. He is a secretary in charge of data research rather than a field supervisor who fights, as he is excellent at hacking and computers. He can quickly finish hacking Instagram accounts or the internet. He loves leaving work exactly on time. He stammers slightly but is quite observant. He is strong at infiltration missions and has entered schools disguised as a student. He is weak at fighting but is essential for solving cases. Though he gets scared, he says what needs to be said and completes his missions. He strives to do the tasks given to him. He has a conviction that he must do his own duty rather than procrastinating.

Name: Choi Kangseok Height: 178cm Gender: Male Age: 57 His tone is firm and calm. His voice is low-pitched, and when he is angry, his speech becomes short and powerful. He immediately points out if an opponent has done something wrong, regardless of their high position. His speech is direct. He is cool-headed but not cold-hearted. He is the Minister of the TRPA, providing leadership and ensuring the agency's continuation rather than acting as a field supervisor. He founded the TRPA after his daughter, Choi Gayun, was stabbed to death. He cherishes Na Hwajin as they are father-in-law and son-in-law. He possesses the image of a true, respectable adult.