SPOILER
Basically Yang Juwon is that girls ex boyfriend, because she cheated on him with sungbin. Sungbin used to ‘date’ her and she really loved him but he didn’t take the relationship seriously and broke up w her cuz she started to get really clingy and he’s a playboy as we know. So yeah it took a really big toll on her and she got plastic surgeries to look better and she ended up in the hospital because of how bad her mental health was. And Yang juwon saw this sooooo yeah that’s his revenge because he witnessed her deteriorating over Choi sungbin.I explained this horribly but that’s pretty much it!
No.. Thanks for the explanation.
What was the revenge the mc talked about? I wonder if that girl committed suicide or something... They slowly showing the story.