
He can start over but he will still be in love with Hyunho. Until that love comes to fruition or plays out, there is no emotional closure. Also, did you notice how much Hyunho changed over the course of the story? We haven't even seen the real Hyunho yet. Ian chopped off his feelings with an axe. It's what you deny that comes back around to bite you in the ass.

please don't say such a horrible things like 'real Hyunho or, getting stab back'!!
fact is that Hyunho dis-respected Ian's feelings. As well as he played with Ian. Hyunho had a chance but he missed it. Ian's heart might have broken already that is why he is still confused with Shiwon's love. So indeed we cheer up when he is finally thinking about returning the affection Shiwon showed when he was broken. Please don't wish for Hyunho to come back because our Ian is finally trying to be true with Shiwon T.T It's true that Shiwon deserves Ian more than Hyunho does, even though Ian loved Hyunho or not( ̄へ ̄)

Tje sequel follows the first part of the story and is in sequence with the main, once included it becomes another chapter.
side story - not part of the main story, doesn't follow directly behind the main story. A bonus.
In writing terms, a sequel is something different. You start with the action, then there's a sequel where the main character thinks about what went wrong, worries over his mistakes, then forms a new plan. The sequel ends, usually at the end of a chapter and the action begins again.

in the same moment that Ian left that sad breakup with Hyundo, Ian turned around, saw Cho at the other end of the parking lot, and immediately fell into a relationship with him! immediately! in the same moment! omg. If that isn't a rebound then nothing is. I was cursing this story and the stupid actions of the characters. Rebound relationships rarely last.

ah but at the end Aeju deviated from the outline and had Hyundo do a couple of mean stupid things such as having sex with Ian and treating him badly. I would bet that that scene is very different in the story that should have happened. The script was altered at the very end to make Hyundo look bad and Cho look good. as I said, I was cursing this story at the end. I'm still mad at Aeju. LOL
If Ian is in love with redhead Hyunho, but he chooses Mr Cha silver hair, then no matter how good silver guy treats him, Ian's heart will always cry out for the red haired guy. I want Ian to choose the red-haired guy Plus silver guy is too boring..
So, Why is everyone celebrating the silver haired guy supposedly winning? Isn't the story ongoing? I don't get it.