Undercover High School
Jeong Hae Seong, a transfer student who seems like he stepped out of a movie, quickly captures everyone's attention with his looks, charm, and smile. But beneath his perfect facade, he's not your average high schooler. Hae Seong is actually an elite NIS agent on a secret mission to uncover the hidden gold of the Joseon emperor. As he navigates high school life, he unknowingly opens up to his classmates, becoming increasingly entangled in unexpected connections. In the process, he uncovers the dark truth behind Byeongmun High, a school deeply corrupted by its obsession with wealth and power. What starts as a treasure hunt soon turns into something much deeper, as Hae Seong seeks not just the gold, but also meaningful relationships. Teaming up with others, he fights back against the corruption in society. His undercover operation, filled with excitement, satisfaction, and a touch of bittersweetness, is about to begin.
- 2025-2025
- 1 season
- Action & Adventure, Comedy, Suspense
- TV-14
Jeong Hae Seong, a transfer student who seems like he stepped out of a movie, quickly captures everyone's attention with his looks, charm, and smile. But beneath his perfect facade, he's not your average high schooler. Hae Seong is actually an elite NIS agent on a secret mission to uncover the hidden gold of the Joseon emperor. As he navigates high school life, he unknowingly opens up to his classmates, becoming increasingly entangled in unexpected connections. In the process, he uncovers the dark truth behind Byeongmun High, a school deeply corrupted by its obsession with wealth and power. What starts as a treasure hunt soon turns into something much deeper, as Hae Seong seeks not just the gold, but also meaningful relationships. Teaming up with others, he fights back against the corruption in society. His undercover operation, filled with excitement, satisfaction, and a touch of bittersweetness, is about to begin.
Season 1 Episode Guide
12 Episodes 2025
Episode 1
The Emperor's Lost Gold
After a botched operation puts Hae Seong and his team in serious jeopardy, the only way for him to salvage his career at the NIS is to accept an assignment that seems almost hard to believe. Hae Seong and his team must infiltrate Byeongmun High School, one of Korea's most elite private institutions, to recover ten tons of gold bars worth a staggering 80 million dollars. With everything on the line, Hae Seong puts on a school uniform, and "Operation Undercover High School" begins.
Episode 2
Spooky Stories
Hae Seong comes dangerously close to blowing his cover while searching for the hidden gold in Byeongmun High School's eerie old building, barely escaping detection by Su A, his sharp-eyed homeroom teacher. As he hears chilling rumors and faces tight security surrounding the building, he believes that's where he'll find the gold. While dealing with school bullies, Hae Seong begins plotting his next move to uncover the dark secrets lurking inside the old building.
Episode 3
Ghost Story Riddles
Hae Seong uncovers a crucial clue hidden within the old building, but Chairwoman Seo quickly learns its potential connection to the elusive gold bars. Sensing the connection, she keeps Hae Seong under close watch.
Episode 4
Joining the Student Council
Hae Seong attends the anti-bullying committee session with a key witness who clears his name, while Dong Min finally finds the courage to stand up for himself.
Episode 5
Student Council
Hae Seong and the team grow increasingly concerned that Su A's suspicions could threaten his undercover mission. However, Hae Seong defies the odds and successfully gains a spot in the student council.
Episode 6
Hae Seong's Father's Notebook
The school's security guard dies, leaving Hae Seong a notebook belonging to his missing father. The revelation is shocking, and he storms the NIS for answers. The answer pushes him away from the mission, and he takes time off.
Episode 7
The 24th Anniversary of Byeongmun High
Su A joins the NIS team as an honorary field agent to help uncover the secret of the third ghost story.
Episode 8
The Plan for VIP Students
After uncovering the possibility of a mole within the NIS, Hae Seong becomes increasingly distrustful of those around him, causing him to question the mission's integrity.
Episode 9
The Mathematics Teacher
Su A recovers in the hospital as Hae Seong exposes the grade-rigging scheme, throwing the school into turmoil.
Episode 10
Retribution
To everyone's shock, Seo Myeong Ju returns to the school. Unimpressed by Hae Seong, she expels him and demonstrates her power by dismantling his team.
Episode 11
The Devastating Truth
The gold bars vanish just as they are within reach, and Seo Myeong Ju suspects Hae Seong has them. In the vault, Hae Seong makes a heartbreaking discovery of his father's remains.
Episode 12
Where The Stars Lead
Despite getting badly injured, Hae Seong manages to call Su A and his team. They conclude that the only evidence they can secure is the flash drive that contains the voice recording of Principal Park murdering Director Kim Hyung Bae.