This app was mentioned in 5 comments, with an average of 1.80 upvotes
You can choose multiple maps to cache, including Google maps. Cache Tokyo at any desired level before going or at your hotel and have fun
Use this: MapsOn, you can choose which map (it includes google maps) and cache all you want with however precision you want.
MapsOn - used it since my first trip, it can cache multiple types of maps on multiple types of zoom.
> But the other thing I love the data for is pathfinding/train timetables.
I don't use pathfinding and timetables ... I look at the map, see closest station, then go =p The funniest part of traveling in Japan is the possibility of get lost without being worried, though it only happened (getting lost) once in Sendai because I didn't realize there was no actual way to cross a highway and had to walk a lot to find a passthru. Found lovely houses and gardens though, so all worth it =p
I check my next day plans on the hotel with wifi.
Download an app with a map and use GPS, couldn't be any easier.
Tip: MapsOn
If you do have connection, google maps is enough