GeocoderJP
This gem is the best solution for geocoding in Japan. Backend is http://www.geocoding.jp/.
Other geocoding gem, such as alexreisner/geocoder is awesome but its backend(Google, Yahoo, Bing, ..etc) is not good especially in Japan.
Compatibility
The following environments have been tested: ruby 1.9.3p0 + OSX Lion
Installation
$ gem install geocoder_jp
Usage
In irb:
$ irb
> require 'geocoder_jp'
> GeocoderJP.get("東京タワー")
=> {"version"=>"1.1", "address"=>"東京タワー", "coordinate"=>{"lat"=>"35.658599", ...
That's it.
In CLI:
After install this gem, you can use geojp command.
$ geojp "東京タワー"
Success!
{"version"=>"1.1",
"address"=>"東京タワー",
"coordinate"=>
{"lat"=>"35.658599",
"lng"=>"139.745443",
"lat_dms"=>"35,39,30.956",
"lng_dms"=>"139,44,43.595"},
"url"=>
"http://www.geocoding.jp/?q=%E6%9D%B1%E4%BA%AC%E3%82%BF%E3%83%AF%E3%83%BC",
"needs_to_verify"=>"yes",
"google_maps"=>"東京タワー, 〒105-0011 東京都港区芝公園４丁目２−８"}