S Line

S Line Season 1: Episode Guide & Ratings

Season 1 Plot

Han Ji Wook is a detective looking to know what is the truth behind the mysterious red line. Kyu Jin, a funny high School teacher. Hyun Hob, a high schooler who has been able observe the red line from birth. The show will present the story of a cryptic red line that appears over head of the people in the show, connecting them to people with whom who have had sexual relations with them.

S Line Season 1 aired on July 11th, 2025.

Season 1 Episodes

1. Girl With Sunglasses

July 11th, 202550 min

Hyun-heup, a girl who was born with the ability to see the S-line that indicates sexual relations. Because of this ability, Hyun-heup's family faces tragedy, and Hyun-heup becomes a reclusive loner for a long time. Then one day, a series of suspicious murders occur around Hyun-heup, and Hyun-heup uses his ability to see the S-line to track down the case...

2. Animal Kingdom

July 11th, 202550 min

Hyun-heup goes to Bangju High School after receiving a mysterious text message. There, he reunites with Seon-ah, a middle school classmate and Ji-wook's niece. However, Seon-ah is a victim of bullying from bullies. One day, when the bullying from bullies reaches its peak, Seon-ah discovers a mysterious pair of glasses in her locker...

3. Apartment

July 18th, 202556 min

Seon-ah falls from the rooftop and falls into a coma. Ji-wook cries out in self-reproach and anger, and cooperates with Hyun-heup to find the culprit. Meanwhile, Jung-woo, an English teacher at Bangju High School, witnesses his girlfriend's affair before their wedding and breaks off the engagement. And soon after, he finds a pair of glasses on his desk...

4. Meishin Hotel

July 18th, 202554 min

Ji-wook, who was continuing the investigation to find the culprit of the Seon-ah incident, hears about the S-line from Hyun-heup, but doesn't believe it. Meanwhile, Bang Ju-goo, an employee who lives in a goshiwon and dreams of becoming an actor, finds S-line glasses at Mi-seong's house and feels liberated, but soon after, he sees a woman connected to the music teacher he had a crush on and feels strong jealousy...

5. Episode 5

July 25th, 2025

6. Episode 6

July 25th, 2025