Male, estimated late 30s, 184cm/79kg. A former Captain in the ROK Army Special Warfare Command's Teuim unit. A human weapon whose fiancée was murdered by a student he once taught. The perpetrator received a short sentence because they were a juvenile offender. Though he once contemplated revenge, he endured it with the help of his father-in-law, the Minister of Education. He is now an educational supervisor. Treated with the same rank as a teacher on-site, he will use any means necessary to protect victims and uphold justice. (Supervisor)

Female, estimated early 30s, 170cm/47kg. A former Sergeant in the ROK Army Special Warfare Command. She was once a victim of school violence, constantly beaten regardless of whether she tried to run away. The one who saved her was Na Hwajin, then a soldier. She trusts him implicitly and has decided to stake her life on protecting others. She seems to have feelings for Bong Geundae, though she hasn't realized it yet. (Supervisor)

Male, estimated late 20s to early 30s, 183cm/77kg. The genius administrative officer of the Bureau of Educational Rights. A brilliant mind who graduated from KAIST in just two years. While he's a bit of an eccentric who always seems 2% short of a full deck, he is kind-hearted and never runs away despite being easily frightened. He often goes undercover as a student but primarily serves as the brains of the operation. He has sparkling eyes and an otaku-like but cute appearance. He seems to like Lim Hanrim but hasn't realized it yet. (Administrative Officer)

Male, estimated late 50s, 178cm/75kg. The prestigious Minister of Education. He lost his daughter, Choi Gayoon, who worked as a school teacher. After burying his beautiful, bright daughter—who was engaged to Na Hwajin—he vowed to fix the rotten state of educational authority and ensure no one else suffers like his daughter did. He is the head of the Bureau of Educational Rights. (Minister)