The actor could return to cinema with a rescue mission set in early Joseon, joining an ensemble that includes Go Youn-jung, Lee Do-hyun and WOODZ.
Seo Kang-joon could be heading back to the big screen with a role in Nambeol, a historical martial arts film bringing together some of Korean entertainment’s most recognizable names.
According to an exclusive JTBC report published on October 13, the actor is discussing an appearance in the film, which will mark cinematographer Lee Mo-gae’s directorial debut.
His potential involvement would place him alongside Lee Byung-hun in a story about nine warriors crossing the sea to rescue captives. It would also offer Seo a new challenge after a career built largely around television roles.
Nine Warriors Set Out on a Rescue Mission
Set in the early Joseon period, Nambeol follows nine warriors with different abilities and social backgrounds who travel to Tsushima to rescue people abducted by Japanese pirates.
The film is described as a hard-boiled martial arts action story. Its premise brings together characters whose differences could be as important to the mission as their fighting skills.
Lee Byung-hun will play Im Eok, the experienced leader of the warriors. According to an earlier production announcement reported by Yonhap, the character is defined by his battlefield experience, firm convictions and cool judgment.
Go Youn-jung plays Ae-ryeong, a woman who loses her family in a pirate attack and enters the conflict to rescue her abducted younger sibling.
Seo Kang-joon Could Take a Major Role
JTBC reported that Seo is being considered for a significant character alongside Lee Byung-hun. Details about the character, including his name and place within the group, were not disclosed.
The report identified Lee Do-hyun, Cho Seung-youn, better known as WOODZ, Park Hae-joon, Lee Kwang-soo and Lee Sang-yi among the actors whose involvement had previously been reported.
Seo’s casting remains under discussion. The report’s description of him as the project’s final puzzle piece signals the importance attached to the potential role, but it should not be read as confirmation that a deal has been completed.
A Possible Film Return After A Year-End Medley
If the discussions lead to a finalized role, Nambeol would mark Seo’s return to film following A Year-End Medley, the 2021 ensemble romance known in Korean as Happy New Year.
The project would also be his first historical action film, according to JTBC, giving him an opportunity to move into a different genre and performance setting.
The casting report follows a major television milestone. Seo won the Grand Prize at the 2025 MBC Drama Awards for Undercover High School, an achievement confirmed by MBC’s official winners list.
That recognition adds interest to his next career move, particularly one involving a large ensemble and a physically demanding genre.
Filming Is Targeted for Late 2026
Nambeol is in the final stages of preproduction, with filming targeted for the second half of 2026, according to JTBC.
The project is also drawing attention because it puts Lee Mo-gae in the director’s chair after an established career as a cinematographer.
A release date was not provided in the casting report. Further announcements will be needed to establish Seo’s participation and the production’s final schedule.
Editor’s Note: The Filmmaker Behind the Camera
Lee Mo-gae’s move into directing gives Nambeol another point of interest beyond its cast.
The Cannes Film Festival’s official records credit him with cinematography on Hunt, which screened out of competition in 2022, and as director of photography on The Good, the Bad, the Weird, presented in 2008.
Those credits connect him to two very different forms of action filmmaking: a tightly constructed espionage thriller and an expansive adventure built around movement and spectacle.
His experience does not establish what Nambeol will look like, but it provides useful context for the attention surrounding his directorial debut. For Seo, a confirmed role would bring a new genre opportunity within a project led by a filmmaker with substantial experience shaping action for the screen.