Is it possible for the appearance of Kangjoo's real father?

I do like the idea of that because I'm curious what would happen.  I think it could be a good opportunity for KangJoo  to get a closure & let go of his attachment issues plus his fixations on the idea that him & his father should have similarities to prove their relationship. Can't guess whether it would hurt him or give him satisfaction, ( I personally think it would hurt him) but I'd really like to see that happen & I believe there could be a chance for his appearance.