What is the S Line trend and why is it sparking backlash? Origin and all you need to know about the Kdrama inspired movement

Recently, following the release of the K-drama series S Line, a trend has been dominating the internet. The trend revolves around the concept showcased in the series, where a girl gains the ability to see red lines coming out of people's heads and connecting them to others.

This line, which can be multiple or singular, connects people to whom they've had s*xual intercourse. Additionally, if one of the people connected to the owner of the red line dies, then the red line also disappears. While many people have had divided feelings about the concept, it began to concern more netizens when it grew into a trend.

Following the release of the show, several people have been participating in the thread where they've been connecting themselves with a red line in edited pictures, such as celebrities, actors, singers, or even people from their circle.

Given that some netizens have also been participating in the trend without knowing its connotation has also resulted in backlash for the trend.

Here are a few of the backlash reactions that landed on the internet regarding the S Line trend:

"S-line is trending on tiktok and FB and the s-line meme is becoming a trend globally. It's so wasted that there's no international OTT" said a fan on X "I will never understand why that whole "SLine" thing is a trend. Wdym you're confidently posting on socmed about how many times you've had s*x? Isn't that supposed to be private? Self-respect where? People are way too comfortable online. Ever heard of a digital footprint?" added another "I hate the sline trend its so annoying how people are publicly revealing stuff like....i don't need to know ur body count or sh*t bruh" commented a netizen

More fans and netizens expressed their concerns over the trend.

"I hate the sline trend where people draw red lines between ships and its always multiple lines .. is no one watching the gawddamn show here" stated a fan "I’m sorry but S-Line trend is just so unnecessary. Well, it’s based off of a movie, so okay but you guys exposed yourself on how many body count you’ve had in real life ? like srsly." said a netizen "Aaaaand fomo people on TikTok are using it to edit on picture of their child not knowing the context, poor kid" commented another X user

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All you need to know about the recent K-drama series, S Line

On July 11, the South Korean thriller fantasy, S Line, premiered on the internet. The show was an adaptation of the webtoon series called S Line, written by Little Bee, and it was released in April 2025. It also holds an interesting cast starring Lee Soo-hyuk, Lee Da-hee, A Rin, Lee Eun-saem, and others.

S Line centers on the mysterious red line that appears above people's heads and connects to those they've had a sexual relationship with. Detective Han Ji-uk, played by Lee Soo-hyuk, seeks to uncover the truth about this line. He forms connections with Lee Gyu-jin, a high school teacher, and Sin Hyeon-hop, a high school student, to solve the mystery.

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While the red line has been invisible to people's eyes, Sin Hyeon-hop has been able to see the red line since birth. The show holds a total of six episodes, and four episodes have been released so far.

Edited by Bharath S