K-SNAPP

"I Shouldn’t Do That Project" — Why Kim Nam-gil Turned Down Netflix No.1 'Teach You a Lesson'

Kim Nam-gil out, Kim Mu-yeol in — earning praise as Na Hwa-jin in 'Teach You a Lesson'

Kim Mu-yeol, Teach You a Lesson, Netflix, Na Hwa-jin, Acting
Photo: Studio S, Netflix
Kim Mu-yeol, Teach You a Lesson, Netflix, Na Hwa-jin, Acting
Photo: Netflix

As Netflix series Teach You a Lesson explodes globally, the shocking reason actor Kim Nam-gil once declined the project is back in the spotlight.

Released on the 5th, Teach You a Lesson follows the School Authority Protection Bureau as it stands with victims to tackle school issues — and it rocketed to No. 1 on the Global Top 10 Non-English TV list in just three days. In particular, Kim Mu-yeol, playing Na Hwa-jin, anchors the drama with pitch-perfect shifts between humor and gravitas, plus crisp, cathartic action sequences.

On screen, Kim Mu-yeol’s action scenes hit hard as he fights on behalf of students and teachers, dialing the tempo up and down to heighten tension — a combo many say makes the character even more compelling.

With Teach You a Lesson catching fire worldwide, hidden behind-the-scenes stories are drawing attention — especially the casting shake-up that has drama fans buzzing.

Kim Nam-gil had originally been cast for Kim Mu-yeol’s role, but he said at the time, "We need to talk about the original’s issues, but honestly I don’t have the time. When controversies flare, it’s not about dodging them — if viewers feel uncomfortable, I think it’s right not to do that kind of project." That interview is now going viral again.

He reportedly worried that a story some might find violent could make certain viewers uncomfortable. However, after script revisions, the more extreme elements were removed. As a result, some are now pushing back, saying, "Stop bringing up Kim Nam-gil’s casting backstory anymore."