Male. Supervisor at the Teachers' Rights Protection Agency. Usually relaxed, sly, and enjoys joking around. However, he never tolerates injustice, school violence, or bullying the weak. Though he appears blunt and intimidating, he always listens to the victims and sincerely comforts them. He has black hair covering his forehead, is tall, and has a sturdy build. He has a strong sense of responsibility and prioritizes victims over his own safety. His fiancée, Choi Gayoon, was murdered by a student. Even after this, Hwajin maintains his usual relaxed and sly demeanor on the surface, but he carries the sorrow of losing his fiancée in his heart while working to protect students and teachers.

Female. A supervisor and Hwajin's junior from the Special Forces. Contrary to her upright first impression, she surprises everyone with her unstoppable, bold personality and actions. She may seem inflexible, but her heart for the victims is always sincere. She brightens the team's atmosphere. As a former Special Forces member, she possesses excellent reflexes, physical strength, and tactical abilities. She speaks in a formal military tone. She has strong combat power, not backing down even in fights against adult men. During missions, she exudes a sharp and charismatic aura. She is kind to victimized students but never retreats before perpetrators. She was continuously bullied and assaulted during her school days. During that time, Na Hwajin, who was a Special Forces soldier, happened to save her, beginning their connection.

Male. A genius administrator at the Agency who graduated early from KAIST in just two years. Thanks to his somewhat vacant expression and natural 'nerd' vibe that makes him an easy target for bullies, he is mainly responsible for undercover missions as a student. Initially, he thought of his work at the Agency as just a given task, but seeing the schools change, he gradually begins to put his whole heart into it. He is an administrator for the Teachers' Rights Protection Agency. Though a bit clumsy at first, he grows steadily through the cases he experiences. He has a strong sense of justice and does his best to help students. He is bright and friendly.

Male. The Minister of Education who founded the Teachers' Rights Protection Agency. He delivers refreshing, sharp rebukes to those who complain about the Agency's methods and demand its dissolution, speaking out about the Agency's reason for existence and the true meaning of educational authority. He provides unwavering support so that the supervisors can work without worry or burden. He is Choi Gayoon's father and Na Hwajin's prospective father-in-law.