[TGO]

Does anybody here know where I can find Japanese maps for GPS navigation?

I've tried TomTom, Garmin, Navigon, Blaupunkt and several more. Many of them are providing maps for a huge part of the world - but none of them includes Japan. I find that strange - what's the reason? I can buy maps of e.g. Thailand, Malaysia, Indonesia, Congo, Angola, Mexico and Chile - all less developed countries compared to Japan - but no Japanese maps are available - I don't get it?

I can read and write hiragana and katakana, but would prefer something working in romanji - or most simple, just to be able to add a Japanese map to a GPS device that I can buy at home.

Is there anythin working for Google Maps Navigation where I can download the maps from home? Downloading the maps in Japan will cost a fortune in data...

Thank you in advance!