Undercover High School: Where is the Gold?

Introduction

With only 12 episodes, Undercover High School blends mystery, romance, comedy, action, and youth genres to engage the audience’s watching experience with a richer story and diverse perspectives. Does it work? Below is my review (after the drama info and character list).

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Drama Info

Drama title: Undercover High School (Native title: 언더커버하이스쿨 )
Alternative title: Eondeokeobeo Hai Seukul 
Genres: Mystery, Romance, Comedy, Action, Youth
Aired: Feb 21, 2025 - Mar 29, 2025
Episodes: 12  |  Duration: 1 hour 10 minutes
Director: Choi Jung In ( 최정인 )
Screenwriter:  Im Young Bin ( 임영빈 )
Where to watch: Viki and Kocowa
Trailer:

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Original Soundtrack

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Synopsis

Jung Hae Seong, an elite NIS agent facing demotion, goes undercover at Byeongmun High School to locate King Gojong’s missing gold bars. Posing as a student, he encounters O Su A, a contract Korean history teacher with dreams of becoming a full-time faculty member. As they grow closer, Hae Seong uncovers the school’s dark corruption. With the help of others, he begins his fight against the powerful forces at play. (Source: MyDramaList)

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Characters

Relationship Chart

Main Characters

Seo Kang Joon ( 서강준 ) as Jung Hae Seong/Jung Si Hyeon

Jin Ki Joo ( 진기주 ) as O Su A/O Bong Ja

Kim Shin Rok ( 김신록 ) as Seo Myeong Ju

Supporting Characters

National Intelligence Service (NIS)

Byeongmun High School Student Council

Byeongmun High School Students

Byeongmun High School Staff

Other Supporting Characters

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Review

Story

Several Genres in Just 12 Episodes

I identified that there is one major genre, which is mystery (the quest for the gold bar), and it’s sustained by the romance that is an unknown factor for both Hae Song and Su Ah and an attractive element for the audience. Since this is only 12 episodes, the drama is made light-hearted with tons of comedic elements. The mystery element will be boring without action scenes with sprinkles of suspense and thriller elements. And lastly, since the story setting is in a high school, Undercover High School also touches the lives, experiences, and coming-of-age stories of students.

I will give the breakdown and explain what to expect from each element, and I will put some details in spoiler tags.

Mystery theme: Where is the gold?

The quest for the gold is the main genre because it spans from the beginning to the end. It means you won’t get the answer I asked above in the title about the gold’s whereabouts till the end. Also, there are some twists. Hae Seong not only gets the answer to his main mission but also a side mission about his father.

Romance theme: How can a legal romance between a teacher and a student be made?

Well, the audiences know from the beginning that Hae Seong is an adult, so the romance between him and Su Ah is okay. But in the beginning, Su Ah doesn’t know that he’s an adult, and neither does the school. Spoiler below:

The romance storyline

Usually, halfway through a romantic drama, the main couple get together or realize they have feelings towards each other. In this drama, from the start after Hae Seong enters the school and lands in Su Ah’s class, she already pays special non-romantic attention to him. Not (only) because he’s handsome, but she suspects he’s a delinquent (he fights some thugs in her mom’s restaurant before the mission). She also suspects he bullies another student. Her special attention makes them close to a teacher-student relationship. Later, she suspects that he’s an adult because of his interactions with the Quizno’s staff (his undercover NIS colleagues). In Episode 6 or 12, Su Ah finds out that Hae Seong is an adult, and she helps with his mission. To accelerate the romance plot, the drama introduces the old romance trope. See below for another spoiler.

What’s the old trope you’re talking about?

The past/childhood connection trope. They are best friends in the first grade. They’re each other’s first love, then he moves away. She already has a thought that he’s similar to her first love when he shows the same habits, for example, disliking and putting away peas. But she shakes away that thought, because her first love is supposed to be the same age as hers, not a teenager. Thus, when they find out that they’re Si Hyeon and Bong Ja from the past hood, their relationship jumps from a teacher-student relationship to a best friends/childhood sweethearts relationship.

Then how to make a legal romance between a teacher and a student?

Well, since the beginning we know he’s an adult, but Su Ah and the public/students don’t know. The public/students know that he’s an adult at the same time when an online rumor with their pictures circulates that a teacher dates a minor. To save Su Ah, he clarifies that he’s not a minor but the same age as the teacher. In addition, he takes a chance to confess to her in front of the class. Notice that he also doesn’t wear a school uniform in the GIF below:

Comedic elements: The agents are like three clowns

Humor in Undercover High School provides a welcome respite from intense scenes of the action, mystery, suspense, or thriller elements or dark storylines of the youth genre elements (bullying, gaslighting), allowing the audience to process complex emotions and themes more comfortably. This is where the drama makes Hae Seong’s colleagues more like clownish characters, especially Ko Yeong Hun and Park Mi Jeong.

Unfortunately, the comedic elements carried by these NIS agents make them look dumb and make the audience criticize the drama. Their skills and experiences as secret agents are questionable, lol!

The Action of the Ace NIS Agent

Well, since the protagonist is an ace NIS agent, we get to see Hae Seong in action, which is fastly satiated in the beginning of Episode 1 by a visceral, exciting one of movement through Seoul stress as Hae Song pursues a thug, usually within a time-critical mission.

In his mission to find the gold bar, although the target place is a prestigious high school, there are high stakes, a clear sense of danger, and life-threatening situations. Among the innocent youths, there are school bullies, and even bigger and stronger villains!

A Nice Touch to the Youth Genre

At first, I didn’t like the school setting in this drama. When the NIS agents have a briefing about the “Undercover High School” mission (yes, the name of the drama is the name of their mission!), I see the similarities between Byeongmun High School and Shinhwa High School from the 2009 Korean drama Boys Over Flowers ( 꽃보다 남자 ), even the school front is the same! Also, the school student council’s arrogance and their bullying are comparable to F4 and their bullying. I hate that almost every youth/high school K-drama contains bullying scenes!

However, as the drama goes, Undercover High School is completely different than the older drama, the bullying case is soon eliminated, thanks to our hero Hae Seong. Then, the youth genre becomes enjoyable to watch: with students facing challenges but overcoming them, endearing friendship, finding their contribution to the class and school, and understanding themselves. Their teacher, Su Ah, with her dedication to the character growth and development of her students, is a major catalyst. She’s motivated to make a change to the school and encourage her students to take action, too.

Characterization

I like both the Male Lead and Female Lead in this drama. They’re both strong in their own ways. I think they both contribute equally to the storyline. Hae Seong, with his sole mission, ends up helping students with their issues. Su Ah, while pursuing her goal to be a permanent teacher in the school, has a greater mission with her dedication to the students’ growth. With his NIS combat training and experience, Hae Seong has the advantage of being a knight saving a damsel in distress. But Su Ah is not a damsel in distress either, she has trained in basic self-defense skills.

My only criticism about the Male Lead is that Seo Kang Joon looks too old as a high schooler, because of his masculine facial features. He is just a manly man, and I can’t believe that only Su Ah is suspicious that he’s an adult.

As for the villain, we have Seo Myeong Ju, a very smart villain with her scheming and gaslighting. However, her characterization is a bit over the top with her obsession and evilness. But again, this drama exaggerates things to the point that we just throw logic out the window to be able to enjoy it.

On the contrary, in my opinion, Seo Myeong Ju’s daughter Ye Na has the best character growth. From a snotty girl who is the student council president due to her mother’s status, Ye Na becomes someone who wants to rely on her own ability, not nepotism. Also, go against her mother’s ambition to make her the top/best student.

Acting

I started this drama because of the leading actress Jin Ki Joo. I fell in love with her cuteness and dimples when I watched her debut as the leading lady in Wednesday 3:30 PM ( 수요일 오후3시30분 ). Undercover High School is the sixth drama I watched with her as the Female Lead. However, I also like her acting. Seo Kang Joon, as much as a lot of ladies watched this drama for him, only Are You Human Too? ( 너도 인간이니? ) that really impresses me. As for the third lead, Kim Shin Rok, she is stereotyped as a villain. But she acts really well as a villain. Her leading role in The Kidnapping Day ( 유괴의 날 ), again as a villain, is unforgettable.

The Visuals

Because of the action genre, we get good chases, fights, and explosion scenes with decent special effects and choreography. The dark and light choice, scene framing, camera movement, and lens choices created cinematic scenes and screenshots. The school location is a European-style castle, which is visually stunning inside and out, as seen above, depicting the main hall of Byeongmun High School.

If you don’t really care about the visual effects in this drama, at least, you’ll be mesmerized by Seo Kang Joon’s puppy eyes with rare hazel color, which adds a distinctive touch to his overall beauty.

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Conclusion

In conclusion, the recent Kdrama Undercover High School manages to mix multiple genres, mystery, romance, comedy, action, and youth, to engage the audience with a short but rich story. And, to answer my question in the article title above: where is the gold? Does it exist, or is it just a rumor, myth, or scheme? Read the Spoiler section below.

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Spoilers

So, where is the gold?

In Hae Seong’s house all along. His late father found a stash of them in school and hid it in the attic. Hae Seong solved his father’s riddle to find them. Mission completed.

Happy, sad, or open ending?

Happy ending.

Spoil me the details of the ending.

Seo Myeong Ju gets a life sentence, and her minion Park Jae Mun is sentenced, too. Hae Seong is reinstated as an NIS agent. Five years later, Su Ah finally gets her credentials as a teacher. Hae Seong is still an NIS agent. An Seok Ho becomes the NIS Director. Ko Yeong Hun and Park Mi Jeong are expecting a baby. An Yu Jeong starts as an NIS agent. Lee Ye Na becomes an artist. Lee Dong Min becomes a Webtoon artist and creates “Undercover High School”. Hae Seong proposes to Su Ah, and the ending credit shows that he’s back undercover as a high school teacher.

When did Su A find out that Hae Seong is an NIS agent?

Episode 6

How did she find out? (Connected to above spoiler)

In Episode 5, she already suspects he’s an adult, not a high schooler, so she spies on him. He reveals his identity to her after she sees him with a body, and he’s holding a gun. She wants to call the police.

When did the school know that Hae Seong is an NIS agent?

Seo Myeong Ju and the principal know right from the beginning that he is an undercover. agent. The students and the rest of the staff know that he’s not a minor in Episode 10. They find out he’s an NIS agent in Episode 11.

How? (Connected to above spoiler)

The villain circulates an online rumor with pictures of Su Ah and Hae Seong together, that a teacher is dating her student. Hae Seong clears up the rumor by revealing that he’s not a minor, but he doesn’t say he’s an NIS agent. He makes up a sad life story. In Episode 11, the school finds out he’s an NIS agent on TV.

When did Hae Seong and Su A get together?

They get close after she finds out he’s an NIS agent and thus helps him with his mission, but he confesses to her in front of the class in Episode 10 (in connection with the above spoiler).