Dear X is a darker-than-expected thriller that follows Baek Ah Jin (Kim Yoo Jung) through a tumultuous childhood to a complicated adult life as a popular actress. Ah Jin appears sweet on the outside, but it’s a front to conceal her antisocial personality disorder (AKA sociopathy). In adulthood, she manipulates people to get what she wants, including her former stepbrother Yoon Jun Seo (Kim Young Dae) and an old classmate who vowed to be useful named Kim Jae Oh (Kim Do Hoon).
The first four episodes premiered November 6, 2025, and are available to stream on Viki. My review is late, but I’m dying to talk about the drama because it practically reached through the screen and grabbed me by the throat. I was locked in, and no other Korean thriller has made me feel that way since The Glory. The plot is engaging, the pacing is perfect, and Kim Yoo Jung’s performance as a young sociopath is truly chilling. I knew she’d kill it—perhaps that’s not the best choice of words.
Introducing: Three Yeses and A No
My review format is probably not what you’re used to, but that’s the beauty of “Kimbap and K-dramas”. Instead of just writing a standard review, I’m going to do something called “Three Yeses and A No”. The “yeses” will be three things I like about a drama. They could be broad like plot, cinematography or characterization; or a specific scene or piece of dialogue. In similar fashion, the “no” will be something I think needs improvement. If you happened to read my writing on another K-drama blog this will be very familiar. I think it’s a good way to keep the review structured and hone in on certain points. There will be spoilers, so read at your own risk.
Feelings about Dear X thus far…
Before I get into my first “Yes”, I want to talk about how I need compensation for the emotional damage episodes one and two caused. They totally caught me off guard. I wasn’t expecting the drama to be so dark! I guess that’s on me because it’s rated appropriately, but still. Some Korean thrillers are afraid to take it there and really dive into topics like child abuse and mental health, but Dear X doesn’t have that problem.
If you read my announcement about reviewing Dear X, I mentioned looking forward to watching it because Kim Yoo Jung is a versatile actress. Her portrayal of Baek Ah Jin needs to win every award during award season. Ah Jin’s eyes are black and fathomless, and there’s no warmth in her smile. It’s merely a curve of the lips. Kim Young Dae’s come a long way since Penthouse, but it’s too early to see if his acting is going to pack that emotional punch, especially sharing the screen Kim Yoo Jung. As for Kim Do Hoon, he’s very convincing as Kim Jae Oh. He’s doing a great job playing a “tough guy” who is really just scared and hopeless. I’ve only seen him in Love Scout (and I just started watching Moving) so I don’t fully know what to expect yet.
The first two episodes moved quickly, but contained a whole lot of story. They showed us how a “monster” like Baek Ah Jin is made, established the characters’ relationships and gave insight into their motivations. I care about all of them—even scary Baek Ah Jin who reminds me of Tomie (she even has the same hair cut in high school). I’m really excited for what’s to come.
YES to Baek Ah Jin’s backstory
Crafting a backstory for a sociopath is delicate work. It has to humanize them even though they do things that make them seem less than human. It has to make the audience care about them to a certain extent or we won’t be invested in the story. Dear X has done this beautifully. From the opening scene where we see a tiny Baek Ah Jin treating the gaping wounds she received from her mom to watching her dad throw her mom’s limp body down the stairs. It’s hard to stomach a small child experiencing things no one should experience. But it’s exactly those experiences that stunt Ah Jin’s empathy. I was still surprised when Ah Jin walked down the stairs to see if her mom was really dead only to discover she wasn’t and ignore her plea for help! It was giving The Bad Seed.
Baek Ah Jin’s cruelness developed early, but those moments are juxtaposed with slivers of emotion. For example, in a flashback to that night, Ah Jin’s dad is sobbing loudly and artificially when the authorities pick up his wife’s dead body while silent, seemingly genuine tears stream down Ah Jin’s face. Her mom was absolutely vile, but it’s still hard losing a parent. Then there’s Ah Jin’s little smile when Yoon Jun Seo picks her up and swings her around for getting into Hankook University. I would’ve missed these glimmers of humanity if I hadn’t been watching so carefully. The screenwriter clearly did their research on antisocial personality disorder, and I’m glad they’re not taking the cartoonish route.
Speaking of Hankook University, when I first read Dear X’s summary I thought it had always been Baek Ah Jin’s dream to become an actress. The profession made sense for a sociopath because it leads to money and adoring fans. So when Ah Jin turns down a talent scout, and we learn she actually wants to study law at Hankook University, my brain starts analyzing the career choice. Lawyers can also be wealthy and prestigious, but am I wrong to think an itty bitty part of Baek Ah Jin wanted to pursue law so people like her dad and Jae Oh’s dad’s can’t get away with torturing their children? Maybe it’s a stretch, but I couldn’t help but go there.
Sadly, Ah Jin’s plans fall apart when her dad finds out where she lives, beats the crap out of her, and steals the tuition money for Hankook University that Yoon Jun Seo acquired through his rich grandfather.
At the end of the day, these tragedies don’t excuse how Baek Ah Jin ruthlessly manipulates people for her personal gain, but they’re certainly an explanation.
YES to the relationships between the characters
The relationship between the characters is another thing that’s done really well. Baek Ah Jin and Yoon Jun Seo’s codependent bond is understandable because neither have good parents. Ah Jin’s dad is a gambling murderer who married Jun Seo’s mom for money, and Jun Seo’s mom is lying to him about his birth father and tried to drown Ah Jin in a bathtub—which Jun Seo witnesses.
The trauma bond isn’t completely organic though. Ah Jin helped it along by telling Jun Seo his own mother didn’t love him when he was sick, lonely, and vulnerable. She preyed on his guilt and isolated him at a very young age. She made herself his world. It’s really twisted, and the drama magnifies everything by weaving in a little romantic tension when they’re older.
Baek Ah Jin’s relationship with Kim Jae Oh is also interesting. They meet when she catches him stealing AirPods from another student’s backpack, and doesn’t snitch. This turns into them running some kind of high school loan shark business together.
Kim Jae Oh comes from a similar background as Baek Ah Jin. He’s from humble beginnings, and has an abusive, mentally ill dad he needs to protect his little brother from. He feels aimless and weak, so he gets validation from Ah Jin using him. They are clearly set up to be kindred spirits. The reason I find their relationship engaging is because Jae Oh’s clearly another tool to Ah Jin, but there’s some nuance. I suspect a tiny part of her cares about him since she knows what it’s like to be abused by a parent. That’s why when Jae Oh accidentally kills his dad and calls her before turning himself in, she shares a few manipulation tactics to win over the jury and shorten his jail time. I don’t think Ah Jin would’ve offered “help” (in her own twisted way) if she didn’t care—especially since she didn’t actually know if Jae Oh would ever be useful to her again.
Finally, there’s Baek Ah Jin’s rivalry with Shim Sung Hee. A lot of dramas have explored how ruthless high-achieving teen girls can be, but Dear X adds a little twist. Instead of mean rich girl versus nice scholarship student, it’s mean rich girl versus sociopathic scholarship student, and this difference made the battle between the girls exciting to watch. I didn’t know what to expect, and I even caught myself rooting for Baek Ah Jin. I had to pause and remind myself they were both doing things that weren’t okay. The back-and-forth for the top spot at the school was like a tennis match, and my jaw dropped when Baek Ah Jin wins after framing Shim Sung Hee as a thief and telling her their teacher was having an affair with her dad.
I just love how complicated every relationship in the drama is. In some, you can see glimmers of something beyond Ah Jin’s need for control (Yoon Jun Seo and Kim Jae Ho) and in others you see a mirror of her toxic traits (Shim Sung Hee).
YES to where the drama is taking us
So far the drama has shown us how Baek Ah Jin became a “monster”. It’s shown us how she formed relationships with the two men in her lives, and how far she’s willing to go to get what she wants. We also learn Baek Ah Jin became an actress out of desperation. She wanted to be a lawyer, but her dad stole her tuition for Hankook University and put her in the hospital, making her miss the enrollment deadline.
Now we’ll get to see Baek Ah Jin’s rise to stardom in a profession that breeds insecurity and isn’t known for doing great things for mental health. We’ll watch her rise just to watch her fall. And I don’t foresee a happy ending. I think everyone in Baek Ah Jin’s corner will discover her true nature and leave her. While that makes me a bit sad for her, I can’t say she doesn’t deserve it after everything she’s done.
NO to Dear X only being 12 episodes?
Pacing is really important to me. The speed in which a plot unfolds can make or break a drama. I’m usually a fan of ten to twelve episodes even though many K-drama fans like the original sixteen-episode format. I just don’t think most dramas have enough plot to fill that many episodes, and usually end up dragging from episode ten to fifteen before cramming the climax and an unsatisfactory resolution in episode sixteen.
But Dear X has me feeling different. The plot is so rich and the characters are so interesting, especially Baek Ah Jin. This is not only a case study on how people become monsters, Baek Ah Jin is going to have a whole roster of men doing her bidding. Right now it’s Jun Seo and Jae Oh, but at the end of episode two another man played by Kim Ji Hoon will be added, and the initial trailers also showed Baek Ah Jin having a fiancé. So with Baek Ah Jin puppeteering all these men, I’d love to see the relationship she has with each of them thoroughly explored. I hope twelve episodes won’t limit that.
Final Thoughts
Like many others, I’m obsessed with Dear X! It’s the first thriller that’s made me this excited in a while. And because our protagonist is a sociopath, I can’t predict what will happen next or how the drama will unfold. All I can do is buckle up and enjoy the ride.
What did you think of Dear X? Did it meet your expectations or fall short?
