Ustumi's dad is a nice guy but I find it questionable how he's dealing with the prejudice against his son (by moving and hiding). He also seems to be relying a bit on Nachi to heal him emotionally.
His dad was aware (I think?) of the prejudice his kid would suffer if he had a kid with his wife, but he still chose to have one. Not saying he shouldn't have, but what kind of life would it be if there was no Nachi? And he couldn't have known that someone like Nachi would come along either.