18+ Drama’s Stomach-Turning Plot Twist Disturbs Viewers With Its Real-Life Parallels
Content Warning
The newest short K-Drama series, S-line, officially started aired on July 11 after premiering at the 8th Cannes International Series Festival earlier this year.
Based on a webtoon, the series follows four individuals: detective Han Ji Wook (Lee Soo Hyuk), homeroom teacher Gyu Jin (Lee Da Hee), Hyun Heup (Oh My Girl’s Arin), and Seon A (Lee Eun Saem). In this world, connections between individuals who have had sex appear as red lines to some individuals, causing drama to unfold around them.

Seon A is the first to discover the glasses that allow the S-Lines to be seen, which results in an accident: she falls from her school’s roof. Han, Seon A’s uncle, investigates his niece’s accident as she lies connected to a respirator, as police want to write it off as an attempted suicide.
Eventually, Han comes into possession of the glasses, using them to try to solve the ongoing murder cases.

At one point, he gets a call about his father, who has disappeared from his care home, only to see that a woman helped him into a taxi. While considering the possibilities, he heads to Seon A’s hospital room, where he notices her S-Line bending towards the door. Han’s father then walks in, and after a moment, Han realizes that Seon Ah’s single S-Line is connected to his father, meaning that he sexually assaulted his own granddaughter.
Han reacts strongly, attacking his father when he realizes this.


The plot twist left viewers in shock and disgust. Some even commented that this happens in real life as well, with no special glasses allowing such crimes to be seen.
Oh the mother of plot twists…
I'm disgusted but not surprised…Men are f*cking trash in this drama.#SLine #SLineEp5#SLineEp6 pic.twitter.com/XCp1pTEf4V
— ♡Ktrauma_enthusiast♡ (@iianamii) July 25, 2025
the hardest pill to swallow is that this really happens in real life. most of the time it’s at home, and it’s someone in the family you thought would protect you, not hurt you. https://t.co/pW8T29hF1W
— kahel 🍊ྀི (@kkaahel) July 26, 2025
i feel sick in my stomach aaaaaaaa https://t.co/reIVSEM8qj
— nisoyyy | kinda ia (@expelliarmooss) July 25, 2025