“S-Line” Ending Explained
“S-Line” aired its finale earlier today. Here is a recap of its 6th and final episode!
Table of Contents
“S-Line” episode 6 recap
We get a flashback to Lee Kyu-Jin finding a young university student. The student was illegally filmed during intercourse, and it spread online, making her life a living hell.
Lee Kyu-Jin saves her from suicide and gives her glasses.
In the present time
Joon-Sun meets up with Hyun-Heup and wishes her a happy birthday. The two end up sleeping together. As they leave the motel, Joon-Sun grabs something to eat, he fetches a cake before the last train but on his way out, gets randomly killed by metal rods dropping from a building. He dies on the spot.
Distressed, Hyun-Heup sits down and cries her eyes out with blood on her hands. She then gets a video from a person who tells her to come to school, Kyung-Jin was kidnapped. She calls the detective who is distressed after finding out that Sun-A was molested by his father. He asks Hyun-Heup if she knew, and she says she’s shocked.
The two drive to school as she tells him someone had been sending her a letter on her birthday each year. As they both run to school, Hyun-Heup enters a room and the detective follows after her. But as she enters the room, she suddenly disappears.
It seems she was transported to a different dimension. She fetches Kyung-Jin and both try to escape the school but no matter how hard they try, they always end up in the same floor. Hyun-Heup hears the detective’s voice and heads to the rooftop.
He also goes to the rooftop but ends up in a room, the room is very odd and people are dressed in white cloth standing around a woman, the same woman who we talked about earlier above. This woman says she was blessed with the glasses that changed her life. Lee Kyu-Jin asks her if she still wants to kill herself and says soon, everyone will be able to see the S-line too. The woman, instead, begins killing all her past lovers removing the red lines she had. She kills the last man she slept with in front of the detective.
As the girls also go to the rooftop, Kyung-Jin loses her mind or is under hypnosis. She picks up the glasses and gets into a fight with Hyun-Heup. She tries to kill her but eventually, Hyun-Heup stops that and crushes the glasses, then, her friend somehow returns to her lucid state. In the fight, Hyun-Heup gets slashed slightly and sees her blood floating up. She is then transported to the same room.
In the same odd room, the detective sees Lee Kyu-Jin who seems to have a million S line over her head as she approaches the people. She showcases his father and tells him why he doesn’t want to avenge his niece. She hands him a knife but instead of killing his father, he tries to stab her but fails. She’s stronger than him, she ends up killing his father on the spot.
He tries to shoot at her but she is unfazed, nothing touches her. She explains soon the world will see the S-line too.
Hyun-Heup finds herself in the room as Lee Kyu-Jin is about to kill the detective. Lee Kyu-Jin tells her she’s blessed and its a gift. Then, the people form a circle around her and as Lee Kyu-Jin is about to stab her, her mother interferes. Her mother dies in her arms explaining she got to see the s-line because of the glasses which is why she killed her husband, it wasn’t Hyun-Heup’s fault.
Regardless, Hyun-Heup gets stabbed by Kyu-Jin and her blood flows up and forms a huge red ball that explodes into millions of lines in the skies. While Kyu-Jin sees this happily, Hyun-Heup stabs her and the people somehow awaken from the state they were in and start running for their lives.
As this ends, they go back on the rooftop and the S-lines are exploding on the skies. The detective tries to fetch the glasses but they fall. Now, everyone is exposed. Everyone can see each other’s red lines.
A while later
Everyone is now trying to live with the s-lines. Sun-A wakes up from her coma and now has a better relationship with her uncle, they never ask each other about anything.
Hyun-Heup is now finally a normal human being. People now wear either masks and glasses or straight up helmets to hide their faces due to this issue.
Hyun-Heup goes to the cemetery to visit Joon-Sun. As she lays flowers next to his grave, she hears Kyu-Jin call out her name, she looks around, there is no one. Again, she is called, but this time, Kyu-Jin is stuck to her calling out her name.
The end.
“S-Line” ending explained- FAQ
Does “S-Line” have a happy ending?
No, it does not. IT was mostly a sad ending.
How does “S-Line” end?
It ends with everyone being finally able to see s-lines. Hyun-Heup is finally a normal student who tries her best to carry on with her life. Sun-a wakes up from her coma and is in a good relationship with her uncle now.
Did Sun-ah wake up?
Yes, she eventually wakes up and goes back to school living a normal life to the best of her ability.
Who was the villain in “S-Line”?
The villain was the teacher, Lee Kyu-Jin. But that doesn’t seem to be her real name just a disguise. She is likely a being but not human.
Does Lee Kyu-Jin die?
Yes, sort of. Lee Kyu-Jin is stabbed by Hyun-Heup after she stabbed her too and she supposedly kills her on the spot. However, in the last scene of the drama, Kyu-jin is somehow alive.
Will S-line have a second season?
Its unknown whether there will be a 2nd season but considering how odd the ending was and how it left audiences with more questions than answers, many have high hopes that “S-line” will return with season 2 soon.
“S-Line” ending- review
I have a pet peeve when it comes to some riskier or controversial kdrama projects…. I get the risk associated with this concept, my thing is this…. If you dare to fund such types of projects, either commit to it and do it well, or don’t do it at all. I will seem angry in this review, and I am only angry because I feel like this could’ve been so much better.
This entire 6-episode drama feels like a massive waste of potential. This ending made me so angry. Why does it seem like the director herself is not 100% on board?
The editing is insanely choppy, the writing is…. Where do I begin with this one?
And the thing is, I haven’t read the original webtoon, and it ended such a long time ago. Even though I did not read the webtoon, I still feel like huge chunk of it is missing. Also, I’d assume if it ended, you could have had a more well-rounded approach to the project, no? Its not like its missing material or that it is so long it’ll be too much to go through. Its on the shorter side, I believe it ran for two years, I believe.
If this was produced by Netflix, which I hate to say, at least, it would’ve been done properly. At least, it would’ve felt like the director could be even more open about the ideas it meant to discuss because it brings up many interesting points.
Additionally, the writing is the most intentionally confusing style I’ve seen in a 2025 kdrama, by a landslide. And one of the choppiest I’ve seen in a while, too. I can see the potential, and I can feel it being wasted. I didn’t hammer in on it in the first episodes because I genuinely believed we’d get it wrapped up properly, but that didn’t happen.
The ideas seem somehow connected but also disjointed, the drama should not have focused on seperate cases of characters that wouldn’t be brought up in the finale or wouldn’t matter much in the grand scheme of things. Why couldn’t you have made this a 10-episode drama? Why couldn’t you have written it more cohesively so we can at least begin to understand the disconnected stories splattered throughout its 6-episode run?
I don’t know, I just… its such a shame this is how it ends. An insanely unsatisfying conclusion.. almost feels like a fever dream, and not the best kind.
Did you like “S-Line” ending?
Noooooo. The entire ep 6 was so bad, it kinda feels like another drama. They fumbled so hard, they could’ve made another season with this kind of plot ugh!