***Spoilers***
I think the drama became a little interesting after ep 18, don't get the wrong idea, I still hate it but the fact that Roy Jang is Tae Min and trying to help his brother by blocking Jae Hee's plan is very heartwarming. I found him very sweet, he's still mad at Tae San because he gave up looking for him but he still loves him and he went with him to the places they visited together when they were little. Also, his adoptive father told him that Tae San would be his son just like Tae Min is; what great family!
However, I don't think Jae Hee derserves a happy ending and a reunion with a good father like that. He became a hateful character, I mean he even want Tae Min to go against his own brother and break the company he built with lots of suffering. But Roy Jang (Tae Min) is aware that Jae Hee wants to break Tae San because of a girl and he will protect his brother. In your face Jae Hee! *evil laugh*
The stupid Mi Do on the other hand is having second thoughts now. Since Tae San finally let her go (I loved it when he said "Back then you were a special person to me, now you're just a girl in the bookctore"), she wants to go back to him and she has the undecisive mind AGAIN! Just choose already woman! But at least she's thinking a little and she was almost able to find out that Roy Jang is Tae Min after she saw him crying in front of their old house (The house that Tae San showed her).