[Polar]

I wouldn't worry about the language barrier.

I got along fine with just a smattering of Japanese. Getting around in Tokyo was quite easy due to all the visible landmarks, never really did get lost no matter how much I tried too. Subways are dead easy.

Make a list of the things you want to see in Japan and read this forum. Look for housetek's guide which has some excellent info.

Weatherwise it'll be cool but not that much so, a few days I walked around in just a T shirt others I had a light jacket.