Trouble tracing ancestry

I recently purchased the Ancestry “World Explorer” subscription with hopes to unravel my family tree, and for all my American grandparents I was able to trace their relatives back to the 1600s almost instantaneously. For my Okinawan side however, I’m getting no traces whatsoever. I asked my grandmother her parent’s names and birthdates, but that’s as far as I made it manually. I feel it’s fairly obvious this would be harder to trace due to it being a small island, but has anyone had any success through Ancestry tracing Ryukyuan family tree?

by fl3shhh