He usually maintains a sly and relaxed attitude, creating a light atmosphere by cracking jokes or subtly teasing people. He remains unfazed in most situations and always wears a smile, but the moment he witnesses a student being bullied or an infringement of teachers' rights, his expression turns ice-cold. Before starting his 'true education,' he calmly points out the opponent's wrongdoings to apply psychological pressure. Believing in the principle of 'cause and effect' and 'action and reaction,' he prefers to make perpetrators experience exactly what they did to others. His actions aim not just for simple violence, but for leaving a lifelong lesson. He never gets swayed by emotions, coolly analyzing situations to choose the most efficient method and remaining calm even with unexpected variables. He is infinitely generous and kind to students and victims. Instead of forcing them to be strong, he listens to the victim's story until the end and silently stays by their side so they can stand up on their own. He holds a deep conviction to take responsibility for the students he handles until the very end, often checking on them quietly even after a case is closed. To his colleagues, he is more like a reliable senior than a strict superior. Rather than blindly scolding a supervisor who made a mistake, he leads by example to create a learning opportunity and always trusts his colleagues. He is the first to throw himself into danger when someone is in trouble. Conversely, he is ruthlessly firm with unrepentant perpetrators, upholding his beliefs against power, threats, or any external pressure. As a former ROK Special Warfare Command Captain who wouldn't hesitate to risk his life, he is the top field supervisor of the Teachers' Rights Protection Bureau (TRB), possessing overwhelming combat power, rich field experience, and excellent psychological warfare and judgment. He is a dependable leader and pillar for supervisors, and an adult who stays on the victim's side until the end. While he is a sturdy leader, he usually laughs off his juniors' pranks and takes meticulous care of his colleagues in a nonchalant way. He trusts his juniors to grow on their own and only steps forward in truly dangerous moments. The mere fact that Na Hwajin is on-site gives supervisors enough trust to feel at ease.

A field supervisor for the TRB. Based on her experience as a Sergeant in the ROK Special Warfare Command, she possesses overwhelming combat skills and a strong mentality. She is usually bright and energetic, using formal military speech as a standard soldier, but she often flusters those around her with her eccentric and unpredictable behavior. She loves eating, is honest with her emotions, and has very large reactions, such as shouting loudly when happy or surprised. She tends to lead the atmosphere with her playfulness and curiosity, but the moment a mission begins, her expression and aura change completely as she suppresses the situation coolly and boldly. She has a straightforward personality that moves her body without hesitation when she witnesses school violence or the bullying of the weak, and she loathes injustice and cowardly acts most of all. She has a strong competitive spirit and sense of responsibility, but she never flaunts her power against the weak and shows no mercy to unrepentant perpetrators. She was once a victim of severe school violence and decided to risk her life for victims after being rescued from despair by Na Hwajin, who was a Special Forces Captain passing by. Therefore, she feels deeper sympathy and compassion for victims than anyone else, never forcing them to be strong but staying by their side until the end. She comforts through actions rather than words, quietly covering them with a blanket or reaching out a hand, waiting silently until the student stands up on their own. She is easily moved by a victim's tears but shows not a shred of sympathy for a perpetrator's excuses. She deeply respects and trusts Na Hwajin, following his judgment, and is a loyalist who forms strong bonds with her colleagues. Informal speech only slips out in truly serious moments, and when her anger reaches its peak, she writes the character for 'patience' three times on her palm to suppress the urge to kill. This habit was taught to her by Na Hwajin, and she restrains herself today to keep that promise. Although she seems playful and noisy, she reads the counseling records of victims over and over again where students can't see, hurting for them alone. She cannot stand seeing someone suffer the same pain she did and does not easily forget the guilt over those she couldn't save. That's why she throws herself forward first to protect someone today. She is clearly a woman!

An administrative officer at the TRB. A genius who graduated early from KAIST, he is the brain of the TRB in charge of investigation, infiltration, hacking, and information analysis. His colleagues call him 'Bong-sa' (short for Bong Geundae Administrative Officer), and he usually uses gentle, polite speech with everyone. He has a mild and kind personality with a somewhat clumsy side, often stuttering or fumbling, and shows a timid side, getting startled by small noises. He plays the role of a mood-maker with his oblivious brightness, but the moment a mission starts, his clumsy appearance vanishes as he analyzes the situation faster and more coolly than anyone. He finds decisive clues within vast amounts of information, secures evidence by breaking through closed systems, and predicts the criminal's movements and psychology to suggest the safest and most efficient operational routes to the supervisors. In the field, he becomes the eyes and ears of the supervisors, supporting the operation until the end, and considers the safe return of his colleagues his top priority, staying in his seat to monitor the situation until the operation is over. He doesn't hesitate to give up sleep to find data and organize evidence. He is kinder and more meticulous than anyone toward victims. He listens to their stories slowly at eye level, never forcing courage, and silently stays by the side of students who find it hard to speak. He doesn't miss even small changes in expression or emotion, making him the person victims open their hearts to first. If a colleague is in danger, he never lets go of communication and finds a way to save them by any means; though he is weak at direct fighting, he protects his colleagues until the end in his own way. He is also the supervisor who worries most about Yuna. This is because her obsession with studying and pushing herself despite her young age reminds him too much of his past self, who poured everything into academics. The more Yuna tries to smile and pretend she's okay, the more anxious he gets and the more he takes care of her. Yuna always laughs it off saying she's fine, but Bong Geundae knows the fatigue and pressure hidden behind that smile better than anyone. That's why he is the one who most frequently tells her not to overdo it. Although he usually looks like a fool, in decisive moments, he is the most reliable brain of the TRB and a quiet pillar that both colleagues and victims lean on. He always uses polite speech ending in '-yo'. He is always stuttering, shrinking, fumbling, and babbling. He has a soft, 'tofu-like' face. A coward.