I am not real sure how helpful this will be, but I did find it interesting.
My Japanese daughter in law has about 270 matches on Ancestry. I have contacted a bunch of them checking on names and their families origins. I found by the time you get around 60 peoples information it becomes a blur.
So I downloaded a small map of Japan that shows major cities, not too much detail to clutter it up. Then I went through all her matches and put a red dot on the map for all the cousins I had info on.
Some interesting patterns emerged. She has a large group of distant cousins in Okinawa. Then a lot of them scattered across southern Honshu. Then only a small cluster in Tokyo. Then a large group in Aomori where she is from and a small cluster in Sapporo.
It was interesting to see the distribution of cousins. I think for some people it might help pin down where a bulk of the family is at, or how far back in time did they move around. This might work better for some than others.