I know how he feels though, It's like waking up from a dream into a nightmare. Someone I once thought was special turns out to be this callous playboy that anyone will do. I feel stupid and betrayed.
Fortunately for Ijun, this is not the case as he will find out much later.
As for me, I just hope I never see him again so I can heal.
I really Ijun, I understand why he would act harshly towards her.
However, I feel sad for the mc, she literally went to hell and back.
The sadness, loneliness and fear she felt when her "adopted" parents abandoned her would make a person break.
So I really wants a happy ending that they both deserve.
I don't feel sorry for Ijun.
He pretends he has a lover, humiliates the protagonist.
Even when she explains everything and looks for proof, he doesn't believe her.
Only when he gets other proof does he believe her, but he never apologizes for everything he puts her through.
He kisses her and the protagonist accepts, as if this were his apology.
He treated her like garbage for a while.
My blood boiled reading the novel, and it boiled even more, because the protagonist didn't defend herself. And she forgave him very easily.
I didn't read the novel. I can't read Korean, I wish I read.
I tries to learn from a few apps but it was too difficult because they just teach the sounds not the words for reading.
What I understand from the story from one of spoilers and the from translated chapters.
Ijun doesn't believe her because she waited so long to tell him the truth and, she didn't explain it well.
I believe they both suffers through the misunderstandings and waste a lot of time being apart from each other.
The story is already fully translated in novelupdate.
But I don't really recommend haha.
I just read cause I was bored.
Don't trust all the spoilers, cause some of them are not really correct... truth to be told the FL did too much, she tried everything to help her family and to explain to Ijun.
He played dirt and NEVER APOLOGIZE, that got on my nerves.

Next season he is gonna be a major jerk.
I got so angry reading the novel