Responses
Yes it would be interesting if his father had the sight as well, but the dragons In the manga actually mentioned his grandfather because they said al be this was years ago. And given that there master was so old and how natsumes parents were out of the picture when he was so young. That's why they believe that it was his grandfather who married Reiko.
We finally get to see natsume's dad face! I hope there more details about his dad on the next chapter too, because i feel like his dad can see yokai too, since the dragon yokai did mention him.