For director and scriptwriter Cho Jang-ho, who has long been fascinated by the rise of livestreaming culture, it was only natural to craft a mystery thriller -- a genre he excels in -- centered on this phenomenon.

To write the scenario, the director said he watched YouTube videos for nearly 10 hours a day for a year, and his binge-watching reached a point where he found himself almost believing everything a YouTuber said.

"If you take a step back and think about it, much of what they say doesn't actually make sense. But when someone speaks with such confidence, it is easy to be misled into believing them," Cho said during a press event in Seoul on Wednesday.

His upcoming film, "Streaming," follows the story of Woo-sang, played by Kang Ha-neul, a self-absorbed YouTuber who claims to be a cold case expert. When he stumbles upon a lead in one such case, he pursues a serial killer, livestreaming the entire process. For him, gaining more subscribers and views is his ultimate goal.

To align the press event with the film's theme, the actor kicked off the event with a livestreamed video, filmed in real time near the venue and broadcast on the venue's big screen.

"When I first heard about the plan, it finally sank in that I would be the only actor attending the press event. But then I thought, 'Why not? It would be fun,'" he said, laughing.

The director had Kang in mind for the lead role while crafting the script, having been deeply impressed by the actor's sincerity and strong work ethic. But it took several years for the director's plan to come to fruition, as Kang enlisted in the military and then gained even more popularity through the 2019 hit romance drama "When the Camellia Blooms.“

"I was absolutely mesmerized by the script. I read it in one sitting," the actor said, adding the script was written in first person, giving it a livestreaming feel.

The movie features a unique structure, with the entire story unfolding in real time through livestreaming, making it feel like an actual live broadcast.

"It was unlike any script I had read before, both in structure and originality," said Kang, who most recently starred in "Squid Game Season 2." "I was drawn into the story, which I felt was very refreshing.“

To portray a greedy, pretentious and narcissistic character, Kang said he drew inspiration from people he would rather avoid.

The film marks the directorial debut of Cho, best known for the mystery novel "The Rapture 1992" (2017) and the web-based novel "Justice.“

"Streaming" is set for release March 21.

<A poster for the mystery thriller "Streaming" is shown in this photo provided by Lotte Entertainment.>

 By Woo Jae-yeon