Kim Jae-won Discusses His Role as Sun-rok in 'Yumi's Cells 3'

Kim Jae-won, who gained fame as the "first love memory manipulator" in the drama "Our Blues," has now earned the title of the nation's favorite younger man. Since his debut in "Our Blues," he has steadily built his filmography, recently achieving success with Netflix's "Lady Dua" and TVING's "Yumi's Cells 3," solidifying his unique presence in the industry. His ability to create chemistry with co-stars and evoke the excitement of relationships showcases his new potential.

"I’m really happy to receive so much attention and love, being called the 'nation's favorite younger man.' Besides that, this project being the third season makes it significant as it wraps up the long journey from seasons 1 and 2. I feel proud that we concluded that journey well," he said.

TVING's original series "Yumi's Cells 3," written by Song Jae-jung and Kim Kyung-ran and directed by Lee Sang-yeob, depicts the romance between Yumi (played by Kim Go-eun), now a star writer, and Sun-rok (played by Kim Jae-won), who unexpectedly enters her mundane life. Based on the webtoon of the same name, "Yumi's Cells" has captured Yumi's life, love, and growth from its first season in 2022 to its third season in 2026.

"I often thought about how deeply one can become attached to a character. I really hope Sun-rok and Yumi can live happily together. As a long-time viewer of 'Yumi's Cells,' I wish for Yumi to live happily for her entire life," he expressed.

Each season of "Yumi's Cells" has built on Yumi's relationships, showcasing her journey of love and growth. In season 1, she met her boyfriend Gu-woong (played by Ahn Bo-hyun) through a blind date, while season 2 featured Yu-babi (played by Park Jin-young), who supported Yumi's aspirations as a writer. Season 3 focuses on Yumi's relationship with her younger boyfriend, Shin Sun-rok. Kim Jae-won portrays the beloved character Shin Sun-rok, adding excitement to Yumi's final romance.

"It would be a lie to say I felt no pressure. It felt like being introduced as 'my boyfriend' to relatives during a family gathering. So many people were watching and had expectations for this character. In the original work, Sun-rok is depicted as a unicorn-like younger man, almost perfect without flaws. While there was pressure regarding that, I also saw it as a great opportunity to portray such a fantasy-like character. Therefore, I prepared for this role with a unique commitment, giving 200% instead of 100%," he said.

Unlike the previous seasons, which each had 14 episodes, season 3 consists of only 8 episodes. Fans expressed disappointment at the shorter format, wishing for more time to explore Yumi and Sun-rok's story. Kim Jae-won acknowledged that a longer format could have allowed for more detailed storytelling but emphasized that the priority was to accurately portray Sun-rok within the given episodes.

"Personally, I think Sun-rok is a bit different from the characters Yumi has encountered so far. He is the type to move forward without hesitation once he is sure. Since he is not a calculating character, I believe we could present his story more compactly. While a longer format would have been nice, I focused on expressing Sun-rok well, regardless of the length of the episodes," he explained.

Kim Jae-won identified Sun-rok's greatest charm as his straightforwardness. He believes that the essence of Sun-rok lies in his unwavering commitment to Yumi once he decides to love her, rather than any physical attributes.

"Many people mention his height and appearance, but I see those as secondary charms. Sun-rok's biggest strength is his ability to move forward without hesitation once he is sure of his feelings. Although there must have been realistic challenges, from the moment he decided, 'I love this person' and 'I will protect Yumi for life,' he moved forward without calculation. I think that’s the main reason Sun-rok could reach marriage with Yumi," he said.

Given that the series is based on a webtoon, achieving a visual resemblance to the original character was also a significant task. Kim Jae-won mentioned that he carefully considered his hairstyle, glasses, and clothing, as well as his demeanor at work and after hours, to embody the character Sun-rok as envisioned by fans of the original work.

"I made a lot of effort to match the physical appearance. At work, Sun-rok has a half-up hairstyle and wears angular glasses to appear somewhat cold. Conversely, after work, he has curly hair down and wears pajamas, adopting a relaxed posture that he wouldn’t show at the office. While I’m not a homebody, I found moments of exhaustion after work relatable to Sun-rok, so I infused some of my own experiences into the character," he shared.

"Yumi's Cells" differs from other dramas in its filming approach. The 'cells' representing characters' emotions require actors to consider their presence even when off-screen. Unlike the seasoned production team, Kim Jae-won, who joined in season 3, needed time to adapt to this unique style.

"I knew from behind-the-scenes footage that the staff read the cells' lines, but I discovered that some lines were read while others were not. Curious, I asked the director, who explained that it depended on whether the scene would be split later. For instance, in scenes where the cells express Sun-rok's feelings or when he seems to deny them, the director requested specific details, like turning his head in a certain direction. Watching the broadcast, I realized how it was directed to show that 'I love this person enough to ignore the cells.' Those aspects were really interesting," he noted.

The romance between Yumi and Sun-rok progressed more rapidly after their mutual confirmation of feelings. Within the 8-episode structure, they had to convincingly navigate their relationship from initial feelings to marriage. Kim Jae-won said he tried to genuinely believe in Sun-rok's love by focusing on his emotions while acting alongside Kim Go-eun.

"Once Sun-rok and Yumi started meeting with certainty, there was hardly any time left. We had to compact everything into just two episodes. Since fans of the original work already know the ending, I thought they would expect to see how the couple reaches marriage and the atmosphere surrounding it. So, I pondered how much Sun-rok could love Yumi and thought about actually loving Go-eun noona as Sun-rok," he explained.

In expressing Sun-rok's love, Kim Jae-won emphasized the importance of loving genuinely rather than focusing on age differences or seniority. He noted that Kim Go-eun's charming presence greatly contributed to shaping Sun-rok's emotions.

"I aimed to love Go-eun noona as she is. The age difference didn’t matter at all. She is such a lovely person, making it easy to immerse myself in the role. During filming, she had a short haircut that reminded me of Ponyo from the animated film 'Ponyo on the Cliff by the Sea,' so I affectionately called her 'Ponyo.' I tried to capture that lovely feeling and gaze in my performance," he said.

In concluding the interview, he cautiously shared his future aspirations. Rather than confining himself to specific genres or characters, he expressed a desire to continue discovering new facets of himself as an actor. For Kim Jae-won, what matters now is becoming an actor who is unafraid to make new choices and not remain stuck in a familiar image.

"What I most clearly desire is to be recognized as an actor who always challenges himself with new roles. I don’t have a specific goal in mind, but as a newcomer, there’s so much I want to try. I’ve never seriously attempted action, so I want to challenge myself in that area, and I’d also like to try historical dramas. I’ve wanted to explore film as a genre, and I recently had the opportunity to do so, filming without regrets. I want to continue challenging myself with things I haven’t done before and become someone who isn’t afraid to take risks."