one of the guidebooks I've got (Italian version of Lonely Planet) suggests that "on very clear days" Mt. Fuji can even be seen from Tokyo.
I guess it takes a lot of luck with weather, and I'm not too confident it will happen (even though I'd be delighted to get at least a glimpse of Mount Fuji!), but just in case ... I was wondering where would be the spots in Tokyo where I may have a chance to see that.
I will be in Tokyo for 4 or 5 days, around 20th April.