Sister's affair exposed, a woman obsessed with delusion's shocking actions... The culprit glasses finally in Detective Ji-wook's (Lee Soo-hyuk) hands... SNS abuzz with the visualization of runaway desires and a turbulent, rapid development! | ABEMA "S Line ~The Relationship You Shouldn't See~"

New Future TV "ABEMA" has begun free streaming of episodes 3 and 4 of the shocking, analytical suspense drama "S Line ~The Relationship You Shouldn't See~" (6 episodes total), which lays bare human desire and privacy.

What is "S Line ~The Relationship You Shouldn't See~"?

"S Line ~The Relationship You Shouldn't See~" is a Korean drama and an analytical suspense series based on the popular webtoon by Kkomabi, the author of the hit drama "Parasyte: The Maxim." It depicts a strange world where desire and privacy are forcibly exposed, asking, "What if your hidden sexual relationships were visualized as red lines?" A mysterious red line (S-line) connecting those who have had physical contact suddenly appears above their heads. This line, visualized through special "glasses," never disappears until one of the connected individuals dies, with the protagonist being the sole exception who can see it with the naked eye. Affairs and twisted relationships hidden beneath the surface of everyday life are successively exposed, and communities built on trust rapidly collapse.

<Spoilers for Episodes 3 & 4 Below>

In episode 3, which has begun streaming, Seon-a (Lee Eun-saem), who fell from the school rooftop, is in critical condition. Detective Ji-wook (Lee Soo-hyuk), consumed by grief, investigates and discovers facts such as Seon-a kissing her boyfriend shortly before the accident. He becomes suspicious of suicide, believing she had no reason to take her own life, and begins to uncover the truth.

Meanwhile, a photo capturing an inappropriate relationship between Hye-yeong, who was bullying Seon-a, and a Korean language teacher is leaked and spreads on the school's anonymous bulletin board. Who leaked the photo? Amidst an unsettling atmosphere, the Korean language teacher from the photo is found dead in his car. However, Detective Ji-wook feels further unease about the superficial and unnatural suicide note left at the scene.

Meanwhile, Jeong-woo, an English teacher who had taken refuge at his sister Gyeong-mi's house after his engagement was broken off, accidentally obtains the glasses. Suspecting his brother-in-law's affair through the glasses, Jeong-woo corners him out of a sense of justice, but the situation takes an unexpected turn.

His sister Gyeong-mi, who rammed her car into the mistress couple's car at high speed, utters, "You did something you shouldn't have," and "I am his mistress." Jeong-woo is confronted with the cruel truth that the family he had known was all a lie. At the end of episode 3, Hyeon-up (Arin) finally confesses to Detective Ji-wook that she can see the S-lines indicating others' sexual relationships and reveals the existence of the mysterious glasses that hold the key to the serial incidents, leading to a furious development.

Episode 4 continues with Detective Ji-wook suspecting Seon-a's fall was not suicide but murder, and investigating the background to see if someone is intentionally distributing the glasses. Meanwhile, Mi-seon, a plain school staff member, picks up the glasses. She secretly wears the glasses in an old motel, peeping through a hole in the wall at a couple's intimacy in the next room, becoming obsessed with delusions as if she were the heroine. Amidst this, Mi-seon's desires spiral out of control when she witnesses a secret meeting between the music teacher she secretly admired and an actress. She attacks the actress, knocking her unconscious, and impersonates her to break into the music teacher's room. Mi-seon incapacitates the music teacher with drugged water and attempts to force herself on him, but in the struggle, she accidentally kills him. Despairing over killing the man she loved, Mi-seon attempts suicide. The first person to discover this tragedy was Hyeon-up, who was coincidentally working part-time at the motel reception.

At the end of episode 4, Detective Ji-wook, who rushes to the scene upon hearing of the incident, is warned by Hyeon-up about the danger, stating, "Everyone who gets the glasses goes crazy without exception." Later, while investigating the scene, Detective Ji-wook finally discovers the glasses, the root of all evil, at the bottom of a bathtub filled with bloody water. As Detective Ji-wook puts on the glasses in front of the bathroom mirror, countless S-lines instantly rise above his head, ending with a shocking development that leaves him astonished.

SNS is overflowing with exclamations of shock and excitement, such as "A continuous series of thrills," "The plot is unpredictable," and "I was surprised by the truth, everyone just watch..." captivating the hearts of many viewers.

Who pushed Seon-a, and who is distributing the glasses? And what madness will Detective Ji-wook, who can now see the red lines, face? "S Line ~The Relationship You Shouldn't See~" is available for free streaming from episode 1 to episode 4 on ABEMA. The final episodes (5 and 6), which await a turbulent development and a shocking conclusion, will be released on July 6 (Mon.) at midnight.

Japan Premiere, Exclusive to Japan: "S Line ~The Relationship You Shouldn't See~" Overview (6 Episodes Total)

Work Page: https://abema.tv/video/title/308-161

Streaming Date: Starting June 22, every Monday at midnight (2 episodes streamed, 6 total)

Episode 3 Streaming URL: https://abema.tv/video/episode/308-161_s1_p3

Episode 4 Streaming URL: https://abema.tv/video/episode/308-161_s1_p4

*When using images, please include the credit: [(c) 2025 SIDUS All rights reserved].

About "ABEMA"

"ABEMA," which will celebrate its 10th anniversary on April 11, 2026, is a video distribution service developed as "New Future TV" aiming for innovation in television. Since its launch, it has been an internet television service that can be enjoyed for free without registration, offering approximately 25 channels broadcasting 24 hours a day, 365 days a year, including a news-only channel with a 24-hour schedule, original dramas, romance reality shows, variety shows, anime, and sports, all pursuing "highest quality or uniqueness."

In addition to the largest number of original episodes in Japan among domestic video services (*), it offers a rich lineup of new hit movies, popular domestic and international dramas, and trending anime, as well as sports broadcasts and online live events. You can enjoy content anytime, anywhere, regardless of time, whether on TV or on-demand. Through a viewing experience that is not bound by location on smartphones, PCs, tablets, and TV devices, we continue to provide content that caters to diverse lifestyles.

Furthermore, "ABEMA Premium" for ¥1,180 (tax included) per month offers exclusive features and content, and "ABEMA Premium with Ads" for ¥680 (tax included) per month allows viewing of "ABEMA Premium" exclusive content with ads.

(*) As of March 2026, self-researched.

For the latest information, please check official social media.

New Future TV "ABEMA" (https://abema.tv/) where you can enjoy free videos and trending content.

"ABEMA" is celebrating its 10th anniversary with various campaigns throughout the year, including special program broadcasts and the "ABEMA 10th Anniversary Free Grand Thanksgiving Festival." Please look forward to ABEMA's 10th anniversary.

"ABEMA" 10th Anniversary Site URL: https://contents-abema.com/10th/