From heartthrob to Joseon-era gangster: SF9 alum finds a new creative outlet before his military enlistment

Introduced alongside Netflix Korea's tentpole "Genie, Make a Wish" -- starring power duo Bae Suzy and Kim Woo-bin -- "The Murky Stream" arrived amid fierce competition during the Chuseok holidays, when streamers typically unleash their most high-profile titles.

The Disney+ historical drama anchored by Ro Woon ("The King's Affection") and Shin Ye-eun ("Jeongnyeon: The Star is Born") surprised many, becoming an unexpected breakout despite the marquee stars of its Netflix rival. The series held the top spot in Disney+ Korea's TV show rankings from Sept. 29 to Oct. 10, when its sixth and seventh episodes dropped. The last two episodes were released Thursday.

For Kim Seok-woo, who goes by his stage name Ro Woon, "The Murky Stream" is nothing short of a turning point. He plays Si-yul, a "walpae" -- a term referring to a Joseon-era (1392-1910) gangster -- who claws his way up from a haunted past, the former SF9 idol sheds the heartthrob exterior that once defined his image.

Ro Woon called the role a gift, a long-awaited chance to shatter expectations.

"I was so happy to finally get a role like this. I've mostly played upright characters, refined young nobles or lawyers with a clean-cut image and pale makeup. But it felt rewarding to know that someone had seen another side of me," he said during an interview in Seoul on Wednesday.

That hunger for depth extended into how he built Si-yul's emotional foundation, a character that, he says, began with a sense of "deficiency" at its core.

"Si-yul is someone whose name shouldn't be called and who has no home to return to. I think having a name to be called and a home to return to represents a person's sense of belonging, so without those things, Si-yul felt like someone detached from society. I approached him as a lone wolf belonging nowhere and wanted to give him a texture like tree bark, as if he were an empty person."

Ro Woon's transformative look in the series prompted a flurry of reactions, including that he was barely recognizable as himself. He relished the response, explaining that such feedback was exactly what he hoped for -- proof that he had fully inhabited the character, rather than being seen merely as himself.

His final project before enlistment -- also his last work in his 20s -- he said "The Murky Stream" feels like both a farewell and a prelude.

"In my early 20s, I was hard on myself, always comparing myself to others. But once I started finding joy in acting, I gradually felt more at ease," Ro Woon said.

"Of course, I was frustrated when opportunities didn't come my way or my ambitions weren't fulfilled. But, looking back, it's those experiences that made me a 29-year-old who knows how to take care of myself."

"Just as 'The Murky Stream' came to me like a gift, I want to enter my 30s, living each day fully and with purpose," he said.

Ro Woon breaks the mold in Disney+ hit 'The Murky Stream'