Actor Kim Yoo Jung is captivating global audiences with her daring performance in the hit psychological thriller ‘Dear X’. The series, which has topped streaming charts in 108 countries, features the former child actress in a complex role far from her previous work. Kim Yoo Jung portrays Baek Ah-jin, a top actress hiding a manipulative and calculating nature shaped by a traumatic past.
From Sweet Roles to a Sinister Character
Kim Yoo Jung’s transformation into the villainous Baek Ah-jin marks a significant shift in her career. She admitted the role was challenging to accept, initially hesitating due to the character’s complexity.
“Baek Ah Jin is a very difficult character to embody, so I was honestly scared to take her on. But after meeting and discussing with the director, I gained enough confidence to move forward,” she shared.
This is not her first antagonist role, but it is her most mature. She reflected that her previous villain role in the 2014 film Elegant Lies was a young character, while Baek Ah-jin is written with a powerful and strong presence that required a different approach.
The Psychological Toll of Playing a Sociopath
To authentically portray a character with antisocial personality disorder, Kim Yoo Jung undertook meticulous research. The director provided her with a list of phrases commonly used by people with the condition, compiled with the help of experts.
“I read about two lines and immediately thought, ‘I shouldn’t read this.’ I felt like I was getting completely bewitched by Baek Ah Jin myself,” Kim Yoo Jung said of the material. She later used it more carefully, as a reference guide.
Her preparation extended to her physical performance. She deliberately altered her gaze, avoiding blinking to create a floating, eerie effect and using her large eyes to show more sclera, conveying a sense of underlying calculation even in calm moments.
The immersion took a physical and mental toll. Kim Yoo Jung reported losing a significant amount of weight, both from her psychological state and a conscious choice to show her character’s declining vitality. She even fainted twice during filming, citing the scene where her character kills her father as particularly draining.
“During filming the scene where my character kills her father and wraps things up, I collapsed, completely exhausted. I was so immersed in the scene that I felt a hazy sensation, as if I were in another space for a moment, and I couldn’t wake up,” she recalled.
A Caring On-Set Environment Amid Dark Themes
Despite the dark subject matter, Kim Yoo Jung emphasized that the set had a positive atmosphere, which helped the cast manage the heavy emotions. She took particular care to ensure the well-being of the child actor playing her younger self.
The actor requested that a counselor be present for the child during filming. The mother of the young actor shared that Kim Yoo Jung was consistently warm and concerned for her comfort, checking in on her frequently.
“Because this is a work that involves a lot of expressions that could be psychologically troubling, I consulted frequently with mental health professionals,” Kim Yoo Jung explained. She advocated for mental health support on set, a practice she believes is necessary for any project involving heavy emotional work.
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Global Acclaim and Audience Reactions
‘Dear X’ has become a global sensation since its release in November 2025. The show has reached the number one spot on streaming platforms like Viki in the United States, Disney+ in Japan, and HBO Max in multiple Asian territories.
Social media is buzzing about Kim Yoo Jung’s performance. Fans on Twitter have described her acting as “magnetic” and “career-defining,” praising her ability to shift between vulnerability and cruelty. One viewer noted the power of her expressions, tweeting, “No dialogue or action, no words are needed, her expression speaks louder than any words ever could.”
While Kim Yoo Jung did not personally root for her character, she is pleased that the portrayal has sparked complex reactions.
“I secretly hoped that viewers would curse at Ah-jin and say, ‘Why is she like that?’ However, surprisingly, there were also viewers who supported Ah-jin,” she said. The evaluation that ‘Baek Ah-jin feels like a real person’ made her the happiest.
The drama releases two new episodes every Thursday on various global OTT platforms.
Also Read: Dear X Episodes 9-10: A Dangerous Marriage Pact and a Bloody Cliffhanger
Credits: en.sportschosun.com, cineplay.co.kr
