Personally I'd rather have Naha for a base, as it has a lower latitude for added boost from the earth's rotation. It's also a second class airport and a JASDF base, has plenty of hangar+ramp space, and a launch would have most of the ascent over water. Seems like a natural candidate for a Japanese spaceport.
I'd certainly prefer it to the sparse Kadena AFB (a small nearby American air base) which is in the Wo2001 addon- I've been wanting to make a base at Naha but have been failing.
I'm also considering Ioutou (Iwo Jima) and Saipan. But for launching spacecraft, not driving taxis around.