http://www.tokyofreeguide.com is an organisation which provides tourists with guides - you'll need to email them two weeks in advance with information about yourselves so they can help plan an itinerary. (Weekends only with few exceptions)
Also here's a page with services provided by the Japanese Tourist Organisation:
http://www.jnto.go.jp/eng/arrange/es...o-z.html#tokyo
This is a tricky question to ask because of the politics of speaking Castillian for some Catalan people (I've met a great many who'd rather chew their own leg off first than say anything in Castillian or use the word 'Spanish') but
Polri - does
everyone in your group speak fluent English?
While it might be nice to think that all the volunteers are comitted to offering their services out of the goodness of their hearts, the truth is that most of them get some real benefit out of providing this service as it provides a useful way to practice their language skills ( ^ ). It is entirely possible that the volunteer networks I've provided links to have some Spanish students who would love to practice Castillian (or even Catalan - unlikely, but also possible). Translating what the guide is saying to someone else in your party can be tiring, and even frustrating, for everybody. I'm suggesting that you may want to consider requesting a 'Spanish' speaking guide in case there is one available.