Google Map Japan and 2 Datums
Currently Google Maps is simply moved their satellite imagery to south east about 450m in the area (shown as a red box : N30-50 and E115-152) to loosely adust to Zenrin's Tokyo Datum based Japanese roadmaps it uses.
But the area doesn't cover some part of Japan (esp. Okinawa islands), and
covers whole North/South Korea, and part of China and Russia.
Same kind of roadmaps are available even for Okinawa in Google Maps.
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