Director Lee Sang-yeob and Kim Jae-won Discuss 'Yumi's Cells' and Shin Sun-rok

Every work contains numerous perspectives. Although the director and actors share the same space and time, their experiences may differ. 'Choi Song-hee's B-Cut' focuses on the vivid behind-the-scenes moments that go beyond the 'A-Cut' captured on screen. It reconstructs the 'B-Cut' moments that were even more intense than the completed frames through interviews with the director and actors. <Editor's Note>
 TVING's original series 'Yumi's Cells 3' (written by Song Jae-jung and Kim Kyung-ran, 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.

Director Lee Sang-yeob, known for his work on dramas such as 'Mr. Baek,' 'Shopping King Louie,' 'Revenge of Others,' 'A Wife Knows,' 'My Solo Love,' 'Half and Half,' and 'My Youth,' has guided 'Yumi's Cells' through all three seasons. The third season serves as the final chapter of Yumi's growth and love story, with Shin Sun-rok at its center. Kim Jae-won portrays Shin Sun-rok, Yumi's last love and the culmination of her long journey.

"It would be a lie to say I felt no pressure. It felt like being introduced as 'my boyfriend' by a precious daughter during a holiday gathering. Sun-rok is like a unicorn, a younger man without flaws. So, there was some pressure. But thinking back, it's an opportunity to play a fantasy-like role. I've always given my best in every project, but this time, I feel like I poured in 200% instead of 100%." (Kim Jae-won)

Director Lee Sang-yeob noted that he saw Kim Jae-won's effort to manage that pressure. Rather than focusing on achieving perfect synchronization, he recognized Sun-rok's potential in Kim's attempt to maintain composure despite the tension.

"When Jae-won walked in, I thought, 'Oh? It's Sun-rok.' Being a rookie actor, he couldn't help but feel nervous. His efforts to hide that nervousness reminded me of Sun-rok. When I saw him sitting neatly, I thought, 'That's how Sun-rok would be,' and I found that endearing. I thought, 'If it's Jae-won, he can do it.'" (Director Lee Sang-yeob)

The tone of the romance was crucial. Sun-rok needed to be youthful but not frivolous, affectionate but not overly sentimental. Kim Jae-won carefully calibrated Sun-rok's excitement while being mindful of this delicate balance.

"I thought it shouldn't be overly sentimental. As a younger man, he needs to convey love, but he must still appear masculine and evoke excitement without crossing into sentimentality. I determined that there's a fine line between sentimentality and excitement." (Kim Jae-won)

What did Director Lee and Kim Jae-won find appealing about Sun-rok? Director Lee identified the character's core as 'twists,' while Kim Jae-won highlighted 'straightforwardness' as a key aspect of the character.

"I think the fundamental aspect is 'twists.' Even when there are twists, if there's no charm, it falls flat, but Sun-rok is genuinely honest and healthy. He has no prejudices. He is a wonderful young man who loves someone steadfastly and runs toward them, making him admirable as a man." (Director Lee Sang-yeob)

"Sun-rok's greatest charm is his straightforwardness. Like the 'one-track general' cell in the series, once he decides, 'I love this woman,' and 'I will protect her for life,' he charges ahead without calculation. That's why he ends up marrying Yumi, right?" (Kim Jae-won)

When did Sun-rok first develop feelings for Yumi? Kim Jae-won believes the answer lies in the second confession scene in the series. Despite trying to suppress his feelings due to the principle of maintaining a professional relationship, Yumi had already become an integral part of Sun-rok's life.

"In my interpretation, Sun-rok's journey is revealed when he says during the second confession, 'I think I liked the writer from the beginning.' That seems accurate. His feelings for Yumi grew, but due to the principle of not dating someone related to work, he forced himself to cut off his feelings. Perhaps he had a crush from the start and gradually became fond of Yumi through Kim Joo-ho. What began as curiosity turned into affection, and he may not have even realized how deep his feelings for Yumi had grown." (Kim Jae-won)

Thoughts on the age difference between Yumi and Sun-rok were also discussed. Director Lee believes that the age gap enhances the dynamics of their relationship and adds to the drama's appeal, while Kim Jae-won noted that he focused on the romance without worrying about the age difference.

"Through seasons one and two, Yumi has matured, and in the original work, there aren't many conflicts in her relationship with Sun-rok. A drama needs conflict, but since there isn't any, we ultimately decided to introduce the keyword 'age gap.' The age difference was intended to add fun when Yumi has a crush on Sun-rok." (Director Lee Sang-yeob)

"I didn't pay any attention to the age difference. Although I'm younger than Go-eun noona, she's such a lovely person that I approached the role with a mindset of loving her in reality. I was able to immerse myself in that feeling." (Kim Jae-won)

'Yumi's Cells 3' consists of eight episodes, shorter than the previous seasons, which had 14 episodes each. While this brevity may be disappointing, the production team opted for a more concise conclusion to Yumi's growth, life, and love story.

"Seasons one and two had 14 episodes each, and I thought, 'Wow, that was long.' Haha. When we decided to conclude Yumi's story about growth and life, it raised many questions. We debated how many episodes to have. The final conclusion from the production team was, 'Even if it's disappointing, let's go with eight episodes.' We aimed to wrap up Yumi's story in an enjoyable way." (Director Lee Sang-yeob)

"I can't control the number of episodes in the project. Haha. I also wondered why it was shorter than the previous series, but I think it's because Sun-rok, unlike previous characters, charges ahead once he is certain. Of course, a longer format would be great, but even in a shorter format, I believe I must give my best performance as Sun-rok." (Kim Jae-won)

'Yumi's Cells' has been a series that follows not just a love story but also Yumi's journey to becoming the protagonist of her own life. For Director Lee, season three represents the conclusion of a work and a farewell to the viewers who have supported Yumi for so long.

"I am truly grateful. 'Yumi's Cells 3' would not have been possible without the love and support of the fans. The fans raised Yumi. Thank you for supporting, cheering, and applauding until the end. Every time I read comments saying, 'I was moved by the last scene,' I felt, 'The viewers share my feelings.' Thank you for being with us until now." (Director Lee Sang-yeob)

"I believe 'Yumi's Cells' has taken a long journey from seasons one to three. I feel proud to have been part of it until the end. As a viewer who followed Yumi's perspective, I hope she lives happily." (Kim Jae-won)