Teach You a Lesson K-Drama Cast and Characters Guide - Netflix Tudum

  • Who’s Who

    Meet the Team Schooling Bullies in Teach You a Lesson

    Juvenile Justice’s Kim Moo-yul and Lee Sung-min reunite to knock sense into violent students in this new K-drama.

    By Natalie Morin
    June 10, 2026

When schools don’t do enough to keep their toughest bullies in line, a different kind of teacher has to step up to help. Enter the Educational Rights Protection Bureau (ERPB), a fictional government agency at the heart of the new action-packed K-drama Teach You a Lesson. The bureau was created to protect victims of bullying and restore order in schools whenever anyone — students, teachers, or even parents — go too far.

The situations in Teach You a Lesson aren’t basic schoolyard taunts or stolen lunch money — they include serious psychological and physical abuse with devastating consequences. Therefore, the ERPB requires a formidable team ready to whip these schools into shape (like, literally). Actors Kim Moo-yul and Lee Sung-min and director Hong Jong-chan reunite for this series after working together on Juvenile Justice (2022). ERPB founder Choi Gang-seok (Lee) and inspector Na Hwa-jin (Kim) apply unflinching ferocity to their pursuit of peace.

Below, meet the squad at the heart of the bureau (including a few ex-military), who’ll stop at nothing to protect students’ rights and restore justice in schools throughout Seoul. 

A gentleman in an all-black suit smiles with ease while a group of students look at him with anticipation.

Kim Moo-yul

as Na Hwa-jin
About the Character

Recruited after serving in a highly secretive, specialized sector of the military, Na Hwa-jin now works as an inspector of the ERPB. Armed with an unshakeable ease and a serious punch, Hwa-jin is the agency’s most valuable asset, restoring order in schools and bringing justice to victims of bullying.

Previously In

Eungyo

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Juvenile Justice
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Follow Kim Moo-yul

A gentleman in glasses and a suit holds up a clear zipped bag filled with pills while addressing a group reporters at a press conference.A gentleman in glasses and a suit holds up a clear zipped bag filled with pills while addressing a group reporters at a press conference.

Lee Sung-min

as Choi Gang-seok
About the Character

As the minister of education and the founder of the ERPB, Gang-seok is employs an exceptionally skilled team of special agents to protect students, and is fiercely committed to the cause.

Previously In

No Other Choice

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Juvenile Justice
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Misaeng: Incomplete Life
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A woman in green jacket looks off into the distance while a man grabs her by the arm as she attempts to break away.

Jin Ki-joo

as Im Han-rim
About the Character

Another former military operative, Ki-joo is an ERPB inspector who takes pleasure in her role. To keep bullies in line, she uses any intimidation techniques she deems appropriate.

Previously In

Undercover High School

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Misty
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A handsome gentleman lies on the ground with a menacing smile as someone stands over him.

Pyo Ji-hoon

as Bong Geun-dae
About the Character

The ERPB’s deputy director, Geun-dae, is more tech whiz than muscle, so he’s often tasked with going undercover for the bureau. 

Previously In

Encounter

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Hotel Del Luna
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