Teach You a Lesson — Characters & Cast

To ensure no teacher or student ever suffers the unprotected fate that befell his late fiancée, Choi Ga-yun.

Begins as a seemingly cynical, brutal enforcer driven by deep personal trauma over the loss of his fiancée. Throughout the series, he evolves from a blunt force weapon into a tactical strategist who realizes that true "education" requires protecting victims long after the fights are over.

Systemic educational reform and honoring his late daughter’s belief in true mentorship.

Operates as the high-ranking Minister of Education who created the ERPB. He navigates political attacks and legal challenges, balancing his institutional duty with the personal grief of losing his daughter. His arc culminates in standing firm against corrupt political powers even when his career is threatened.

Eradicating abuse through direct action so no student feels as helpless as she once did.

A former Special Forces sergeant whose abrasive behavior and explosive shouts hide her own history as a former victim of severe bullying. Over the course of the season, she learns to channel her rage strategically, taking on undercover ops and becoming an empathetic protector for victimized female students.

Using his intellectual talents to support justice and protect his teammates.

A brilliant KAIST graduate and civil servant who starts out unaccustomed to violent confrontations. Across 10 episodes, he develops field courage, going undercover into dangerous gambling rings and executing cyber warfare tactics that prove essential to the team's survival.