Nokia N95 service and GPS service in Tokyo, Japan

To the group,

Using a Nokia N95 8GB and Nokia Maps, is it possible to obtain a
detailed map to Tokyo? I can currently (from Canada) see a general map
of highways, but not a street level map.

If so, where can I obtain such a map ?

Furthermore, will I be able to provision the device once in Tokyo? Can
I just plugin a japanese SIM card, for less than a month of service?

Thank you for your help,
Max