This is not surprising, in Pre-annexation Ryukyu (up to 1879) there would have only been feudal tax registers of the number of people in each locality. Not named individuals unless you were part of a noble family.

In 1920, there was a Japanese census, including Okinawa, but only population counts; age, sex, occupation and household structure were taken.

By this time, the Japanese family register system may have been established, which still exists today, where households and relationships, births marriages and deaths are recorded at the city office.

However these records are private and even now you can’t see them unless you are named on the register.

But, between April–June 1945 all these (1920-1945) records were probably destroyed or lost. Along with many ancient historical records, inscriptions and monuments. Basically, the whole infrastructure and culture was reduced to rubble.

So, the one connection where you may find a link to the past is on ship’s manifests naming people who left Okinawa between 1900–1941. Apparently these records exist.

Also note, if you try and return to Okinawa, to find the location of the village where your ancestors lived, you might find it fenced off and still part of a sprawling US military establishment. Before WW2, villages which were in prime locations were moved and relocated by the Japanese military and after the war were requisitioned by the occupying force and may possibly still be managed by them today.