http://www.rosettastone.com/personal/languages/japanese
I know that English isn't uncommon in Japan, but there are only so many places that "eigo o hanasemasu ka" will fly.
And yes, bring a shitload of money. I ended up spending something like $135 a night on a decent room (even getting a discount, and the room wasn't one of the best) and like $20 a meal not including decent dinners, which ran more like $60.
Oh, and do your homework regarding transportation.