Trending Korean Actor Divulges His Real Life Reaction While Filming A Kiss Scene

Yumi’s Cells 3 serves as the latest installment in a franchise that has redefined the romantic comedy genre in South Korea by blending live-action storytelling with 3D animation to represent the protagonist’s internal thoughts and emotions. In this season, Kim Jae Won takes on the role of Soon Rok, a publishing house editor who eventually becomes a central figure in the life of Kim Yumi, played by the acclaimed Kim Go Eun. Soon Rok is characterized by a "sweet face but a sharp tongue," a duality that Kim Jae Won has been praised for capturing with precision.

The Iconic Bungeoppang Kiss Scene and Real-Life Reactions

One of the most discussed moments of the season involves a romantic encounter centered around a "bungeoppang" (Korean fish-shaped pastry). The scene, which was designed to be a turning point in the relationship between Yumi and Soon Rok, quickly went viral across social media platforms for its blend of innocence and high-tension romance.

Reflecting on the scene during his interview, Kim Jae Won expressed his satisfaction with the final edit. "I think it came out very well," he remarked. "Watching Soon Rok on screen, I was amazed at how such an innocent guy could make one feel so thrilled. It was a more exciting kiss than a real one." This statement highlights the actor’s professional immersion, suggesting that the staged chemistry between the characters often transcends the technicality of the filming process.

Perhaps more revealing were Kim’s comments regarding his physical reaction to the scene. Fans of the show had pointed out a specific detail where Soon Rok’s legs appeared to tremble or "go weak" following the kiss. Kim confirmed that this was not a calculated acting choice but a genuine physiological response. "Fans also caught the moment when Soon Rok’s legs went weak after the kiss. My legs actually went weak, and that was well captured," he admitted. Furthermore, a subtle gesture where Soon Rok wipes his lips after the kiss—a detail that added a layer of realism and bashfulness to the character—was revealed to be an unscripted ad-lib. Kim noted that seeing himself act so naturally during the broadcast was a surprising experience even for him, leading him to question if he had consciously intended the movement.

Contextual Background: The Evolution of the Yumi’s Cells Franchise

To understand the weight of Kim Jae Won’s performance, it is essential to look at the history of the Yumi’s Cells series. Based on the hit Naver webtoon by Lee Dong-gun, the series follows the daily life of Kim Yumi, an ordinary office worker, through the eyes of the "cells" in her brain. These cells represent her various emotions, such as Love, Reason, Hunger, and Anxiety.

The first two seasons of the drama, which aired in 2021 and 2022 respectively, featured Ahn Bo-hyun as Goo Woong and Jinyoung as Yoo Babi. Both actors received high marks for their portrayals of Yumi’s boyfriends, creating a high bar for whoever would step into the role of Shin Soon Rok. In the original webtoon, Soon Rok is often cited as the "endgame" or the ultimate partner for Yumi, making the casting for Season 3 a subject of intense speculation and pressure.

Kim Jae Won’s casting was seen as a strategic move by the production team. Standing at 187cm with a background in modeling, Kim fits the visual profile of the "tall, stoic, yet caring" male lead that has become a staple of the "noona" (older woman/younger man) romance subgenre. His previous roles in King the Land and Our Blues established him as a versatile actor capable of delivering both comedic timing and emotional depth.

The Production Environment and Creative Freedom

The revelation that the lip-wiping gesture was an ad-lib speaks to the creative environment fostered on the set of Yumi’s Cells 3. Directed by Lee Sang-yeop, the production has been noted for its collaborative atmosphere. Ad-libs are often encouraged in K-dramas to break the rigidity of a script, allowing actors to inhabit their characters more authentically.

In the case of Yumi’s Cells, the live-action segments must be meticulously timed to sync with the animated "cell" sequences that will be added in post-production. Despite these technical constraints, Kim Jae Won’s ability to inject natural human reactions into the performance suggests a high level of comfort with his co-star, Kim Go Eun. Kim Go Eun, a veteran in the industry, is known for her ability to create palpable chemistry with her leading men, a factor that likely contributed to Kim Jae Won’s authentic reactions on set.

Chronology of Kim Jae Won’s Rise to Stardom

Kim Jae Won’s journey to becoming a "trending actor" has been marked by a series of high-profile projects that have showcased his range:

1. Early Career (2021-2022): Kim began his career as a model before transitioning to acting. His breakout role came in the omnibus drama Our Blues, where he played the younger version of Cha Seung-won’s character. His portrayal of youthful first love resonated with audiences.
2. Mainstream Recognition (2023): He gained wider recognition through the JTBC hit King the Land, where he played a flight attendant. His character’s sub-plot provided a refreshing romantic dynamic that often rivaled the main couple in terms of viewer interest.
3. Breakthrough Lead (2024-2025): With roles in series like Hierarchy, Kim solidified his status as a leading man capable of carrying a show. His ability to play complex, often brooding characters made him a favorite for high-concept dramas.
4. The Soon Rok Phenomenon (2026): Being cast in Yumi’s Cells 3 marked a pinnacle in his career. The role of Shin Soon Rok is iconic in Korean pop culture, and Kim’s performance has been credited with successfully bringing the webtoon character to life while adding a modern, realistic edge.

Impact on the K-Drama Industry and Global Streaming

The success of Yumi’s Cells 3 and the viral nature of Kim Jae Won’s interview reflect broader trends in the South Korean entertainment industry. The shift toward OTT (Over-The-Top) platforms like TVING has allowed for more experimental storytelling and higher production values. TVING, which has been aggressively expanding its original content library to compete with global giants like Netflix and Disney+, has found a flagship hit in the Yumi’s Cells franchise.

The "fish-shaped bun kiss" is a prime example of "micro-moment marketing." In the digital age, small, relatable, and visually appealing scenes are often clipped and shared on platforms like TikTok and X (formerly Twitter), driving viewership and international interest. Kim Jae Won’s candid discussion of his "weak legs" adds a layer of "humanity" to his celebrity persona, fostering a deeper connection with his fanbase.

Analysis of the "Sister Viewers" Demographic

Kim Jae Won specifically mentioned "sister viewers" (nuna fans) in his interview, acknowledging the core demographic of the show. In South Korean media, the "nuna" demographic—women in their late 20s to 40s—is a powerful economic and social force. They are the primary consumers of romantic dramas and often drive the popularity of rising male actors.

The character of Soon Rok is designed to appeal to this demographic. He is professional, respectful, and exhibits a "gap moe"—a Japanese term used in fan circles to describe a contradiction in a character’s personality that is perceived as endearing. In this case, the contradiction lies between Soon Rok’s sharp, professional exterior and his flustered, "weak-legged" reaction to romance. Kim Jae Won’s real-life reaction mirrors the character’s internal state, blurring the lines between actor and role in a way that fans find particularly compelling.

Conclusion and Future Outlook

As Yumi’s Cells 3 continues its run, the focus on Kim Jae Won’s performance is unlikely to wane. His interview with Sports Chosun has provided a rare glimpse into the physical toll and psychological immersion required for high-stakes romantic acting. By acknowledging his natural reactions and ad-libs, Kim has positioned himself as an actor who values authenticity over a polished, artificial performance.

The industry will be watching closely to see how Kim leverages this momentum. With rumors of new film projects and international brand endorsements on the horizon, the actor is poised to become a mainstay in the global Hallyu wave. For now, he remains the "innocent guy" who managed to thrill audiences and himself through a simple, yet masterfully executed, kiss scene involving a fish-shaped bun.

The success of the series also reaffirms the viability of webtoon-to-drama adaptations when handled with care and creative freedom. As the boundaries between live-action and animation continue to blur, Yumi’s Cells stands as a testament to the power of relatable storytelling, bolstered by a new generation of actors like Kim Jae Won who are not afraid to share their real-life vulnerabilities with the world.