Hello fello JP hikers!
I am looking for suggestions on GPS/GLONASS/EURONAV (GPS preferred) handhelds for a very long hike across Honshu! I have been investigating the Garmin Venture Cx as a possible option, but wondered if there's a standard in Japan. In addition, I need a unit that supports a good map feature set for hiking (topo would be great!) of said island. Anyone have any suggestions?

I don't know about the unit but the map that you want is here:

http://uud.info/en/

The price is 8,400 (about $75 USD). Make sure your unit ships with Garmin MapSource, some units don't. You will need that software to load the maps. I think there is third-party software that you could use in lieu of MapSource, but you are on your own. This map is much much better than what Garmin sells at a fraction of the cost.

Of you can go at it the hard way and get the raw data from the Japanese Geographical Survey Institute.

http://www.cast.uark.edu/jpgis/jpdnlm.html

It ships in 3 CDs for 7,500 Yen. You can then use third-party software to look at the data and to load said data onto a GPS.

If you go for door number two, please let me know how it works for you, I'm curious.

Last but not least, I'm working on a Japan hiking site for the Hyakumeizan, a list of mountains depicted inthe 1964 collection of essays by Mountaineer/Author Kyuya Fukada. On the mountain pages you can get Google and Topo maps for all the mountains on the list:

http://www.japangazetteer.com/

hi

This site has good maps in Japanese:

http://route.alpslab.jp/
it includes profiles. I don't know how many hikes are in there for each place, but I am sure there are a good number altogether. Worth checking out. I know they have downloadable data points I believe compatible with Garmin GPS.

Have Fun.