Watch: Seo Kang Jun Struggles To Fit In At High School In "Undercover High School" Preview

Feb 21, 2025

MBC’s upcoming drama “Undercover High School” has shared a hilarious sneak peek of its first episode!

“Undercover High School” is a comedy action drama about a National Intelligence Service (NIS) agent who goes undercover as a high school student to track down Emperor Gojong’s missing gold.

Seo Kang Jun will star as Jung Hae Sung, an ace NIS field agent who disguises himself as a student at Byeongmun High School as part of a secret mission. Initially, Hae Sung tries to remain focused solely on his mission, but before he knows it, he winds up getting increasingly involved with the students and incidents unfolding at school.

The newly released preview of the drama’s premiere begins with Hae Sung giving himself a pep talk on the roof before making his way into class. After letting out a deep sigh, he puts on a determined expression and declares, “Let’s try this!”

However, once he’s in the classroom, Hae Sung can’t stop himself from dozing off in the middle of class. When teacher Oh Soo Ah (Jin Ki Joo) wakes him up by placing a hand on his shoulder, Hae Sung’s secret-agent training and instincts kick in—and he startles everyone in class by immediately jumping up and moving to strike her. Although Hae Sung awkwardly apologizes right away, Soo Ah is not appeased, and she retaliates by angrily hitting him on the head with the papers in her hand.

Things don’t get any easier for Hae Sung when class is over: as soon as the bell rings, two female students rush to his side to try to get closer to him. Calling him “transfer student,” one of them asks for his social media username. But when she uses an abbreviation that the older Hae Sung doesn’t recognize, he responds with visible confusion, leading the other student to ask in disbelief if he doesn’t know the term.

Hae Sung initially plays off the awkward moment by pretending like he’s just joking around, but he ruins his own scheme by incorrectly guessing what the term stands for. The preview ends with a frustrated Hae Sung complaining to someone on the phone, “This is different from [the slang] I learned! What in the world does [this term] mean?!”

Check out the full clip below!