K-star So Ji-sub on Agent Kim Reactivated’s breakout success

SEOUL – Agent Kim Reactivated was a summer phenomenon few in the South Korean television industry saw coming.

The 10-episode revenge thriller series wrapped its run on July 25. Ratings peaked at a nationwide series high of 23.1 per cent, according to Nielsen Korea.

The dramatic surge cemented the project as one of South Korea’s defining television hits of 2026 – with veteran star So Ji-sub anchoring the show’s massive breakout as a long-established name among the country’s action leads.

Playing the titular Kim – a former special operative on a desperate mission to save his kidnapped daughter – the 48-year-old actor’s convincing performance and combat skills earned him a new title in domestic media circles: the Korean Liam Neeson. That screen persona, however, stands in contrast to the actor himself.

Off-screen, So is notably reserved and soft-spoken. At a recent interview in Seoul, he smiled quietly as he reflected on the project’s massive footprint.

“Honestly, it feels a little like I’m being pranked,” he said. “I’m still wondering, ‘What’s going on?’ and feel a bit dazed by everything. When we first started, the team talked about how great it would be if ratings could simply cross the 10 per cent threshold.”

Caught off guard

The show’s upward ratings trajectory caught the cast and crew entirely off guard. “Everything about the momentum was surprising,” So said. “From the premiere numbers to the steep climb that followed, and the fact that the viewership sustained at that level, it was all unexpected.”

Uncertainty had loomed over him throughout production. He recalled confiding in director Lee Seung-young during filming that he had no idea how the public would react, even joking about early retirement should the series flop.

“When I’m working on a project, I usually have a baseline sense of whether audiences will respond,” he said. “But with Agent Kim Reactivated, I really couldn’t predict it. I even told the director, ‘We both think this is strong, but if viewers reject it, maybe we should start planning our retirement.’”

Having recently anchored the hard-hitting noir Netflix series Mercy For None (2025), So said he was looking for another physically demanding project, and Agent Kim Reactivated landed on his desk at an opportune moment.

“After returning to heavy action in Mercy For None, I developed an appetite for another physical role. And beyond the set pieces, the core story resonated with me. I was also eager to explore the dynamic of playing a father to a daughter.”

His performance ultimately earned a second comparison with a major Hollywood star in recent years.

“Last time, I was the Korean John Wick, and now, I’m the Korean Liam Neeson,” So said with a laugh, referring to the John Wick character played by Keanu Reeves. “Neeson is an actor I hold in high regard, so the comparison is flattering.”

He added: “We even joked on set about how wild a crossover between the worlds of Agent Kim Reactivated and Neeson’s Taken (movie trilogy, 2008 to 2014) would be.”

Critical consensus has largely highlighted the show’s taut pacing and punchy payoffs, but So attributes the show’s staying power to its narrative anchor.

“Industry tracking noted the fast pace and cathartic resolution, but I believe the emotional core did the heavy lifting,” he said. “From pre-production, I approached it not merely as an action project, but as a drama about family bonds. I think that emotional groundwork is what truly resonated.”

Second chapter of career

The series has marked a clear inflection point in So’s public image, with fans increasingly addressing him by his character’s name – Manager Kim – a career milestone he equates to his breakout era.

“If I’m Sorry, I Love You (2004) launched the first major chapter of my career, I believe Agent Kim Reactivated marks the beginning of the second,” he said.

At 48, So has no intention of stepping back from physically demanding roles. Instead, he maintains a rigorous daily routine to stay camera-ready for stunt work.

“I feel confident in my physical conditioning for action,” he said. “It’s a space I want to continue occupying as I mature. I keep a strict routine even during downtime, training twice daily so my body stays mobile – boxing in the mornings and strength conditioning in the afternoons.”

With the finale still fresh, So is aware of the growing talk around expanding the franchise, though he said such plans remain uncertain.

If there is a second season, the primary hurdle will be constructing a compelling catalyst for the protagonist, said So.

“The core creative challenge will be framing a new central conflict,” he said. “Kim doesn’t have a wife in the lore, so we can’t repeat that tragic loss, nor can we put his daughter back in jeopardy.”

As for his immediate slate, he is weighing his next steps carefully, acknowledging that the massive ratings of Agent Kim Reactivated have set a high bar.

Yet, he remains open to pivoting back towards lighter fare, citing a recent broadcast rewatch of his hit 2013 project Master’s Sun as inspiration.

“I’d love to venture back into romantic comedy,” he said. “Though I wonder if the market has space for mature, adult-led romcoms today.” THE KOREA HERALD/ASIA NEWS NETWORK