So Ji-sub: The Star Who Never Ages, the Actor Who Never Fades [Interview]

The man who once broke the nation's heart as a relentless romantic has become a father who will not back down from any danger for the sake of his only daughter. Time spares no one — yet somehow it seems to have passed him by. An ordinary father's desperate, all-consuming fight for his child: not even thick-rimmed glasses or a cheap, ill-fitting suit could dim his effortless cool.

"It feels like I've been pranked. I'm honestly still in a daze."

So Ji-sub — the star of "Agent Kim Reactivated," who never seems to age or wear down — sat down with a reporter at a cafe in Jongno-gu, Seoul.

The afterglow of the drama lingers long after its finale, a testament to the extraordinary love and attention it received. The SBS Friday-Saturday drama "Agent Kim Reactivated" wrapped its run on Saturday with a finale viewership rating of 23 percent, becoming the second-highest-rated drama in SBS history. For So, returning to SBS for the first time in 13 years, it was a result beyond anything he had dared to hope for.

"When the ratings hit 15 percent in the second episode, I thought, 'What is happening?' Then when it crossed 20 percent, all I could think was, 'What is this? Can this really be happening?' It was one surprise after another."

Everyone who watched "Agent Kim Reactivated" talks about So Ji-sub. Beyond simply playing the lead, his performance — which matched the original webtoon with near-perfect fidelity — is inseparable from any discussion of the show. The moment an outwardly ordinary middle-aged man unleashes the power he has kept hidden for years, the plausibility of what is essentially a fantasy narrative rests entirely on So's presence.

The resolve burning in his eyes as he vows to find his daughter, the weight behind every punch, the raw and fearless action sequences — these are the reasons viewers could not help but root for him. So himself, however, sees it differently.

"My share of the success isn't large. It's a result that everyone worked together to achieve. If you take away actors like Choi Dae-hoon, who played Seong Han-su, or Yoon Gyeong-ho, who played Park Jin-cheol, I don't think the ratings would have been even half of what they were."

The cast of "Agent Kim Reactivated" delivers intense, unfiltered action throughout the series — and So Ji-sub, long regarded as a master of the genre, is no exception. "Because I work out consistently, I don't feel any physical strain from action scenes yet." The confidence is well-founded.

"This time, since I was playing a father of a certain age, I wanted to project a sense of weight rather than looking too physically sculpted. That also meant a little less pressure to diet, which was nice (laughs). I like action where the emotion shows. In 'Agent Kim Reactivated,' I made sure the emotion came first and the action followed — I think that's why viewers found it so satisfying and cathartic."

The outcome was remarkable, but the process was even more rewarding. So Ji-sub, Choi Dae-hoon and Yoon Gyeong-ho — the trio dubbed the "Dad Avengers," each of whom had worked with the others on previous projects — grew far closer through this one. The atmosphere on set was warm and lively. The actors' ideas and improvisations found their way into nearly every scene, a sign that the set was both freewheeling and intensely collaborative.

"Gyeong-ho is brilliant at channeling physical energy through his body, and Dae-hoon is incredible at calculating everything and translating it into precise, articulate performance. I tend to act without words, letting my eyes do the talking — so when the three of us came together, I think we created a really interesting synergy. Honestly, I think they're both geniuses."

Over more than 30 years as an actor, So has come to understand that no project is made alone. It is why he kept insisting, almost apologetically, that his own contribution to the show's success was minimal. That conviction also explains the gold gifts he gave to the entire crew of "Agent Kim Reactivated" — a gesture expressing his hope that the hard work they shared would become a cherished memory. The tradition began with "Gwangjang," a Netflix series released last year.

"There was a scene where we had to stand in the rain. It was so cold the ground was freezing over. And yet not a single crew member frowned or showed any sign of reluctance — everyone gave everything they had. I was deeply moved and so proud. These gifts are my way of hoping that the time we spent together on set becomes a warm memory for everyone who was part of it."

Born in 1977, So Ji-sub turns 50 this year in Korean age. The word "middle-aged" seems to fit him nowhere — yet the number is not without meaning to him. "As I get older, every single project and character becomes more precious," he said, adding that he hopes to keep doing what he has always done: giving his all, quietly, through his performances.

"It's sad to see friends I used to work with gradually disappearing from the scene. I ask myself, 'How long can I keep doing this?' Acting is hard, but it's fun — and that's why I want to keep at it. My style isn't one of intense emotional swings, but I've come to think that is my acting. I want to keep showing my style, in roles that suit my age."

Many viewers are already looking forward to a second season of "Agent Kim Reactivated" — and So is no different. Despite the drama's record-breaking run, he said he would be happy if a second season "just clears 10 percent." The 20-percent barrier that "Agent Kim Reactivated" broke still feels unreal to him.

"When I work on a project, I want everyone involved to be rewarded, not to come away at a loss. For myself, I just need enough to make it easier to choose my next project. If there are awards at the end of the year, I hope the show receives many of them. In a second season, I expect the broader world of the original story to branch out in many more directions."