Teach You a Lesson — Ending Explained

Throughout the season, the mystery behind the establishment of the ERPB centers on the murder of Choi Ga-yun—the daughter of Education Minister Choi Gang-seok and fiancée of inspector Na Hwa-jin. Ga-yun was a dedicated teacher killed two years prior by her former student, Cho Gyu-cheol.

In the late-season arc, Cho Gyu-cheol is released from juvenile custody. He aligns with corrupt Assemblyman Hwang Gi-tae, who seeks to abolish the ERPB to protect high-level political interests. Gyu-cheol establishes a hidden drug distribution network inside schools, using students to sell illicit substances.

The key plot twist occurs in Episode 10: Na Hwa-jin publicly punches Cho Gyu-cheol during a staged confrontation. This seemingly reckless act gives Assemblyman Hwang the political leverage to shut down the ERPB officially. However, the shutdown is a deliberate ruse engineered by Na Hwa-jin and Minister Choi Gang-seok.

By appearing disbanded, the team goes completely rogue, catching Gyu-cheol's syndicate off guard. Mobilizing teachers the ERPB had protected in earlier cases, the team gathers evidence, intercepts drug supplies, and dismantles Gyu-cheol’s ring. In the final showdown, Na Hwa-jin corners Gyu-cheol. Though tempted to execute him in revenge for Ga-yun's murder, Hwa-jin chooses not to kill him, proving that the ERPB stands for justice rather than blind vengeance. Assemblyman Hwang Gi-tae is arrested, and the ERPB's mandate is officially renewed.

1. The Power Fantasy Reading: Views the show primarily as a cathartic vigilante action spectacle—an artificial sanctuary where suffering victims receive immediate, satisfying payback that real-world legal systems fail to provide.

2. The Institutional Critique Reading: Interprets the ERPB not as a glorification of force, but as a severe warning. In this view, the bureau's radical existence highlights how broken society becomes when formal administrative channels choose self-preservation over moral duty.

3. The Conservative vs. Progressive Educational Debate: Critics debating the ending view the show through opposing political lenses: progressive critics argue it dangerously advocates for corporal punishment and state overreach, while conservative defenders argue it exposes the unintended chaos caused by overly lenient juvenile laws.