2025 saw a slew of blockbuster K-dramas released on the streaming screen. From gut-wrenching slice of life moments to theatrical comedy periodicals, there was a piece of pie for everyone. The trend of webtoon adaptations maintained momentum as well, with the likes of Netflix hits Weak Hero Class 2 and The Trauma Code: Heroes on Call. Leading the webtoon train this time round is Dear X, a devilish 12-episode thriller starring Kim Yoo-jung at the centre of it all.
On the surface, lead character Baek Ah-jin has it all: beauty, brains and a seemingly kind demeanour. But underneath lies a darker persona–one stemmed from years of household violence, and bloomed through survival of the fittest as she navigates her turbulent high school years. Naturally, as an outward perfect all-rounder achiever, she becomes the centre of unwanted attention. This soon proves not to be a problem as she relinquishes those against her, labelled ‘X’, with unnerving cruelty that cuts to the bone.
She’s not alone. Childhood friend Kim Jun-seo, played by Kim Young-dae, stands by her side as she continues to seek vengeance against her peers. Once a rock and pillar of trust, Baek soon learns he is the author of her ultimate downfall. In her shadow also lives Kim Jae-oh, starring Kim Do-hoon, with whom she finds an unexpected ally. Their shared history of a rocky home creates an enduring connection, one that evolves into a bond of devotion.
It’s a twisted tale of power, friendship and retribution as their lives become irreversibly entangled. Below, Kim Young-dae and Kim Do-hoon take us behind the scenes of this thrill ride, as they share filming challenges, on set moments and personal takes on the ending of Dear X.
What aspects from the original webtoon did you embrace in your character?
Kim Young Dae: I thought it was important to reflect the subtlety of the change in Jun-seo’s emotions—even with slight movement or expression, he is always able to express a range of emotions in the most extreme situations.

How do you think this show resonates in today’s world and what lessons can viewers take away from your character?
Kim Do-hoon: The series explores various ways people express love, care and support, as well as the emotions one displays during the process of achievements and loss. Rather than learning a lesson, I hope viewers will empathise with how Jae-oh sincerely gives his all and sacrifices for the people he trusts.
Kim Young-dae: To me, Dear X shows the gap between love and reality—and how one compromises their belief. Jun-seo is not perfect, but he is someone who tries to protect himself from an imperfect world. I hope that him wavering encourages viewers to always show empathy.
What was the biggest challenge when preparing for your role while filming?
Kim Do-hoon: The role of Jae-oh greatly differs from my personality and past roles. I’ve often played characters who are typically composed and cautious, but Jae-oh wears his heart on his sleeve and is free- spirited. Being so different from who I am, I was initially worried about portraying him—yet during our first meeting, the director encouraged me to make the character my own, giving me the confidence to fully immerse myself in the role.
Kim Young-dae: Jun-seo and his emotions are intricately entangled in his relationships—the biggest challenge for me as an actor was figuring out the psychological state of each character and to pinpoint the exact moments when his feelings begin to shift.

If you had one scene or characteristic from your character you hope viewers never forget, what would it be?
Kim Do-hoon: The scenes that stayed with me the most are the ones where Jae-oh partners discreetly with Ah-jin. There’s usually an emptiness to him, but when it comes to Ah-jin, he is a completely different person. I hope viewers can feel the subtle shift in those scenes and notice Jae-oh’s complexity in his emotions that even Ah-jin fails to see.
What was the most memorable moment on set?
Kim Young-dae: A scene where Jun-seo and another character enjoyed some drinks at Ah-jin’s home—while short-lived, that scene reflects how ordinary and happy the characters were.

Personally, are you rooting for Baek Ah-jin to rise or fall?
Kim Young-dae: Personally, I want Baek Ah-jin to fall.

How would you summarise Dear X in three words?
Kim Do-hoon: Sacrifice, complex and emotional.
Watch Dear X on HBO Max now.