Responses
Well, by how this story goes on, I guess Hajin's father maybe had an affair and Hajin is the product of it. So that's why his current mother hates him so much because: 1. Hajin stole her actual son's spot and opportunity and privilege, 2. Her husband cheated on her. Or it could be the other way around that the guy is Hajin's mother's products of cheating and that's why the father is picking up Hajin to be their son and hide the other one.
If Hajin is not her mother's actual son, then who's his real mother then? His father said he saved him from death when he was a baby, so how about his actual mother?
And that actual son of his mother said Hajin is fake, does it mean he should be the real one? I really don't get his family at all. The real Hajin is really pitiful.
I hope Seonwoo will accept his father's offer since he will definitely need it to protect Hajin (yes I know it's not right thinking what his father's family did to his mother). I'm pretty sure Kim Shin loves Hajin as well so I hope he will keep protecting Hajin too (I love him huhu but sadly only the real Hajin should answer his feelings).