Back when they were in the same middle school, he (Jiwook) gangraped Juyeon and posted the video publicly. His (Juyeon) mother saw it and went into shock, who is now in a psychiatric ward. I do not know what happened to Juyeon's dad or to Jiwook's parents. I do not know anything beyond the red room arc (the manhwa is already past that) because the way it was described in the novel just made me feel...
There comes a point where revenge starts to look more like torture than the justice deserved.
Oh! I'm not saying that Jiwook doesn't deserve some extent of it, but... is this really the only way? I know I sound naive and stupid and sheltered and other stuff but...
Why is Juyeon torturing himself to the point of trying to relive the experience where Jiwook is in his position, which is being the victim? Is this really the path of revenge he wants to go through? Jiwool never even remembers no matter how hard he tries... (I skipped to the ending after the red room arc because I wanted to know if it gets better, healthier.)
Anyways—I hope I'm adding some information to the story (haha) But to summarize, they just aren't good people. No one deserves what the other did to the other, but they did it anyways.
What did that guy even do to get this much treatment? He is so pitiful theres just this solemn acceptance that he's never gonna be normal after this if there is an ending for him.