Koseki for great granpa from Okinawa?

i do not live in japan and need a copy of a koseki for my great grand father who i believe is from Okinawa, he migrated out of Japan around the 1900's and am doing some genealogy ? is it possible to do so without actually going to Japan? all i want are some names to put my family tree together? please does anyone know what i can and should do where do i start?

Sorry but I guess it may be difficult.
1) Do you know the place where he was born?
Koseki belongs to each municipality, not prefecture.
2) Many of koseki in Okinawa were burnt out in war.

Anyway you should consult a consulate.

niiaju,

If you can find out where his koseki is located, you can obtain copies by sending the fee to the city hall. As suggested, you can start by talking to your local Japanese consulate.