Director Lee Sang-yeob Reflects on 'Yumi's Cells' and Fan Support

"The core of this story is empathy. Since Go Eun is a character who shares a similar life experience with Yumi, I wanted to maximize that connection. Yumi is a relatable character, like a younger sister you see around you. However, if you look closely, there are also shining aspects to her character that I wanted to highlight."

'Yumi's Cells' tells the story of an ordinary woman, Yumi (played by Kim Go-eun), who experiences love and growth alongside her cells. Beginning with Season 1 in 2022 and culminating in Season 3 in 2026, the series has carefully chronicled Yumi's life and development.

Director Lee Sang-yeob, known for his work on dramas such as 'Mr. Baek,' 'Shopping King Louie,' and 'My Love from the Star,' has guided 'Yumi's Cells' through all three seasons. After such a long journey, he expressed deep emotions about concluding the final season.

"It felt like finishing a big assignment. I worked hard, and it felt rewarding to hear that it was done well. As I wrapped up the final season, I felt quite emotional. The viewers seemed to share similar feelings, which made me realize I wasn't alone in that experience."

Season 3 of 'Yumi's Cells' follows Yumi, now a successful writer, as an unexpected character enters her life, leading her to laugh, cry, and fall in love once more. While the original story includes characters Gu Woong, Yu Babi, and Shin Sun-rok, the drama focused on the narrative up to Season 2, resulting in some adaptations, including shifting some of Shin Sun-rok's episodes to Yu Babi (played by Park Jin-young).

"When I first thought about what story to tell with this original work, I aimed to include Yumi's romance, love and breakup, and her growth as a writer. So, in Seasons 1 and 2, we focused on her relationship with Babi and her debut as a writer. At that time, I wasn't even thinking about Season 3. However, due to the overwhelming love for Seasons 1 and 2, we prepared for Season 3. I was quite anxious, thinking, 'What should I do?' and collaborated closely with the writer. Both of us are fans of the original work, so we pondered how to create a conclusion that everyone could accept, which led us to Season 3."

In Season 3, the romance between Yumi and Sun-rok is restructured around a so-called 'hate-love' dynamic, with a more significant age gap between the two characters than in the original work.

"In the original, Yumi and Sun-rok's relationship has many sweet moments, but the conflicts are relatively minor. However, for the drama to be engaging, there needs to be a clear progression of conflict. So, we introduced the 'hate-love' concept. As a successful writer, Yumi develops a crush on Sun-rok, and I thought it would be interesting to have some barriers in her feelings. By increasing the age gap, it allows Yumi to naturally question whether it's okay for her to have feelings for him. We made these changes to enhance the drama, and I was a bit surprised by how well it was received."

The casting of Kim Jae-won as Shin Sun-rok generated significant interest. In the original, Shin Sun-rok plays a crucial role in Yumi's final romance and marriage narrative, making him a central figure in Season 3.

"During the audition, I immediately felt he was 'Sun-rok.' Since it was a meeting with both the writer and me, Jae-won, as a newcomer, was understandably nervous, but he tried hard not to show it. That effort made him seem even more like Sun-rok. He wore a thick suit, like armor, and sat neatly, which reflected Sun-rok's character. He looked both cute and impressive. I thought he could definitely pull it off."

Yumi's love interests have varied each season. After Gu Woong and Yu Babi, Season 3 introduces Shin Sun-rok, with the production team emphasizing the chemistry that arises when Yumi connects with her partners, as much as the fidelity to the original work.

"I believe Yumi looks good with tall men. Jae-won's dark, clear eyes also match the webtoon image well. Most importantly, I thought their two-shot would be beautiful. During the first meeting, I felt relieved and thought, 'Thank goodness, he can do this well.'"

Reflecting on Yumi in Season 3, Director Lee Sang-yeob praised Kim Go-eun, who has been with the series throughout all three seasons. He noted that she continues to exceed expectations. Particularly, Yumi's character, starting the season as a successful writer with a sense of ease and ennui, aligns well with the experiences Kim Go-eun has gained as an actress over time.

"She is such a talented actress. Even in Seasons 1 and 2, she consistently delivered more than I expected. I often found myself chuckling while monitoring her performances. In Season 3, Yumi begins with a sense of ease as a successful writer. That aligns perfectly with the diverse roles Kim Go-eun has taken on and the experiences she has accumulated. She expressed Yumi's feelings of ennui and limitations as a successful writer exceptionally well."

Director Lee Sang-yeob believes Yumi's charm lies in her relatability rather than glamour. She is a character who seems like someone you could meet in everyday life, but if you look closer, you find something special. He noted that Kim Go-eun captures this essence beautifully.

"Yumi's greatest strength is that she appears ordinary, yet shines when you look deeper. We all encounter people in our daily lives who are striving in their own ways. This aspect was crucial in the original work, and I wanted to ensure it was well-represented in the drama. During our preparations, we discussed the importance of contemporary empathy. We aimed to highlight relatable aspects of characters living in a similar era, and Kim Go-eun executed that brilliantly."

The combination of live-action and animation is another distinctive feature of 'Yumi's Cells.' As the seasons progressed, the technical quality and detail of the animation improved.

"Rather than just increasing the scale, I think the details have improved. For instance, the scene where Yumi's town experiences a flood shows a significant evolution in the water effects from Season 1 to Season 3. Water animation is quite challenging, but we've reached a point where we can implement it effectively. The fire effects are also difficult, but we can now create them more realistically. The heart fever scenes have become much more vibrant, thanks to technological advancements and accumulated know-how."

The final wedding scene is significant for fans of the original work. Director Lee Sang-yeob, also a fan, wanted to capture this moment faithfully. He aimed to preserve the original imagery as much as possible, and in doing so, he found himself expressing his own fan sentiments.

"As a fan of the original, this was a scene I really wanted to include. The original writer had written a scene that I aimed to replicate as closely as possible. There is a scene in front of the curtain, and while it was challenging to make it exactly the same due to the wedding venue's structure, I made some adjustments to the background while still channeling my fan enthusiasm. After finishing, I felt relieved and somewhat like I was marrying off a younger sister. I genuinely hoped Yumi would be happy."

Throughout the three seasons, Yumi has been accompanied by Gu Woong, Yu Babi, and Shin Sun-rok. Director Lee noted that each character has its own strengths and significance. He explained that Yumi's growth was completed through her relationships with these characters.

"I think the feelings we invest in characters are all similar. From a directing perspective, Woong was the most sympathetic character, while Babi was perfect but had a fatal flaw. However, he was also someone who supported Yumi's journey as a writer, which deserves praise. I envisioned Sun-rok as a boyfriend who would bring excitement. After experiencing anxious relationships in her twenties, I wanted him to be someone Yumi could feel secure with. I believe that Woong and Babi's presence made Sun-rok possible. The ability to explore various romantic experiences and growth is one of the strengths of 'Yumi's Cells.'"

The success of Season 3 was largely due to the support of fans. In his closing remarks, Director Lee expressed gratitude to the viewers who have supported Yumi throughout her journey.

"Season 3 would not have been possible without the support and encouragement of fans who loved Seasons 1 and 2. I believe the fans raised Yumi. Thank you for cheering us on and being with us until the end."