Netflix's latest suspense thriller, "The Frog," delves into the often overlooked victims of tragedy — those who, like a frog hit by a carelessly thrown stone, suffer severe consequences from events they never sought to be part of. This dark exploration of murder and its ripple effects captivated the actors involved from the outset.

“While murder stories typically spotlight the victims' families or the killers themselves, the narrative of those who become secondary victims — like a frog struck by a thoughtless stone — is rarely told,” said Ko Min-si, who portrays Yoo Seong-a, a guest of the series’ central guesthouse.

The series’ English title, "The Frog," draws from an old Korean saying, “A frog can be killed by a carelessly thrown stone,” underscoring the profound impact that thoughtless actions can have. In contrast, the Korean title, “In the Forest Where No One’s Around” (translated), echoes the isolation and unseen suffering that permeate the eight-episode series.

The series follows the story of Jeon Yeong-ha, the owner of a guesthouse, and Koo Sang-jun, a motel owner, whose peaceful lives get disrupted by unexpected guests as they get pulled into turmoil that they never wanted to get involved in.

Directed by Mo Wan-il, known for JTBC’s acclaimed drama "The World of the Married" (2020), the series stars Kim Yun-seok as Jeon Yeong-ha and Yoon Kye-sang as Koo Sang-jun.

Ko, alongside her co-star Yoon, discussed their roles in the series during a recent interview held in Jongno District, central Seoul.

In "The Frog," Seong-a, played by Ko, exhibits psychopathic tendencies that unsettle and disturb Yeong-ha, played by Kim.

“I was worried whether I could pull off such a complex character even before I was cast,” Ko said. The actor confessed that she initially doubted her ability to portray Seong-a, as she believed her image was far removed from that of a killer. It was only later that she learned director Mo had chosen her for an “unexpected reason.”

"Director Mo said he saw a glimpse of Seong-a in me when I briefly looked down at my shoes before responding to his compliment on them,” Ko said, noting that she had worn dress shoes to the meeting, a rare choice for her.

In the series, Seong-a’s unsettling presence is enhanced by her revealing wardrobe — a deliberate choice by Ko to emphasize the character’s raw, animalistic nature. The actor even slimmed down to 43 kilograms (95 pounds) to accentuate Seong-a’s lean, almost skeletal frame.

“I chose outfits that revealed my back to showcase Seong-a’s primal quality by highlighting the bones and muscles,” Ko explained. The role, she added, was particularly meaningful, as it came at a time when her self-esteem was at its lowest.

“During filming, I gained not only confidence but also a deeper understanding of myself.”

Since its release on Aug. 23, "The Frog" has been described by some viewers as an “unkind drama” for its refusal to neatly explain every detail, including the characters’ backstories. Ko acknowledges this critique but believes it was necessary to convey the series’ deeper message.

“We didn’t want to focus on the killer,” she said. “The drama is meant to explore the psyche of the frog that gets hit by the stone. The killer's actions needed to be incomprehensible to better highlight the mental state of the surviving victims.”

For Yoon, he also acknowledged the feedback of it not being viewer-friendly.

“As a suspense thriller, it’s meant to be challenging and provoke curiosity,” Yoon said. The series, which intertwines two separate narratives, presents an unusual structure for a drama, one that Yoon found intriguing.

“I’ve never seen a drama where two distinct stories coexist within the same show,” he said. “Sang-jun’s and Yeong-ha’s stories can’t fully overlap, which made me curious about how they would eventually converge.”

For his role, Yoon shed 14 kilograms in three weeks, aiming to accurately portray his character’s later years. However, his transformation elicited an unexpected response — people told him he looked younger.

“It was devastating,” he laughed, “but I gave my best for the role.”

Yoon said the project was different to others he had starred in. “Sometimes, there are projects that make me feel like I'm being consumed [as an actor],” he said. “But with this drama, I felt re-energized, as it allowed me to explore different facets of my craft and collaborate with talented actors.”

"The Frog" is currently streaming on Netflix, continuing to captivate audiences with its haunting portrayal of the unintended victims of tragedy.

BY KIM JI-YE [kim.jiye@joongang.co.kr]