Holiday Ayo - 

The Korean drama S Line has become a hot topic across various social media platforms, including TikTok, since its official release on July 11, 2025.

It's not only the blend of thriller, fantasy, and mystery genres that has captivated audiences, but also the drama’s unique visual concept that has drawn public attention.

The term “S Line” has been widely discussed due to a striking visual element—a red line above the heads of certain characters. Clips from the show featuring these red lines have been widely reshared by TikTok users, sparking widespread curiosity among netizens.

Interestingly, the number of red lines varies from character to character—some have one, two, or even several lines, while others have none at all. This visual detail has led viewers to speculate about its meaning.

The series stars Lee Soo Hyuk, Lee Da Hee, and Lee Eun Saem, each portraying characters involved in unraveling the mystery behind the red lines.

According to an explanation posted by TikTok user @wahyuhasianta, the red line symbolizes that a person has had sexual intercourse. “The red line above the head indicates someone has had sex. The number of lines can differ—one, two, or none at all,” the user wrote in their post.

S Line presents an intriguing narrative in which the red lines are only visible through a special device or by individuals with certain abilities. This concept has become a focal point among viewers, sparking public discussion on the meaning and societal commentary behind the series.