S-Line is a new fantasy thriller series featuring OH MY GIRL's Arin. It has made history as the first Korean drama selected for the long-form competition at the Cannes International Series Festival 2025. The series also won the Best Music Award, solidifying its global presence.
The drama premiered on Wavve on July 11. It is based on the webtoon by Komabi and blends elements of psychological thriller, fantasy, and social commentary into a compelling character-driven story.
Arin breaks away from her cheerful idol image to play the complex role of Shin Hyun-heup, a woman who can see supernatural "S Lines," or red threads connecting people who have had sexual relationships.
"We are honored to be recognized on such a prestigious stage. It's a milestone for Korean dramas and for Arin's career," said a spokesperson from the production team.
Plot: Red Threads of Connection and Secrets
In a world where most people cannot see these mysterious red strings, Hyun-heup isolates herself due to the emotional burden of her rare ability.
After witnessing a gruesome murder linked to these lines, she begins a journey to uncover dark secrets and hidden desires.
As she meets others who may or may not see the lines, the story deepens into an exploration of intimacy, trauma, and power.
Read More: Can You Trust What You See? 'S-Line' Blurs Lines Between Desire and Reality
Unlike the webtoon's anthology format, the drama adaptation follows a tightly woven, character-driven narrative.
The red strings serve as a visual and thematic metaphor for relationships, guilt, and unspoken truths, adding tension and a philosophical angle to each episode.
Arin, recognized for lighter roles in The World of My 17 and Alchemy of Souls, impresses viewers with her mature, understated performance.
Her portrayal of Hyun-heup, highlighted by a blunt bob and monotone voice, reflects a study in controlled emotion and quiet strength.
"Arin's performance is hauntingly still yet emotionally resonant," said one Cannes Series Festival judge.
Her co-star, Lee Eun-saem, excels as Kang Sun-ah, a bullied teen who gains the ability to see S Lines and seeks revenge. The transformation of her character within just two episodes has left viewers and critics impressed by her depth and intensity.
Mixed Reactions: Stylish but Flawed?
While it has received acclaim for its ambitious idea and strong acting, S-Line has also encountered mixed reactions regarding its direction and tone.
Critics point out abrupt shifts in tone, noting moments of unintended comedy, including a scene where Detective Han Ji-wook (Lee Soo-hyuk) is shown connected to numerous women by floating red strings.
Some action scenes, like a delayed reaction to a crime scene or over-the-top shootouts, have been criticized for undermining the series' psychological realism. However, some argue that the hyper-stylization contributes to the show's unique identity.
"It's not perfect, but S-Line dares to be different. It visualizes what society tries to hide—intimacy, secrecy, shame—and forces us to look," wrote one reviewer.
With only the first two episodes released, anticipation is growing both at home and abroad. International distributors are reportedly in talks with Wavve following the series' buzz at Cannes.
As audiences eagerly await new episodes, the central mystery remains: Will the S Lines create connection and healing, or plunge the characters into greater chaos?
Read More: Is It True? Lee Soo Hyuk to Lead New Webtoon-Based Drama 'S-Line'
