You can't do much in a day: take the train from the airport and make sure you take a fast/direct one as this can get you to the centre of Tokyo in about an hour. You also need to make sure you catch a fast/direct train back out to Narita which means you'll have to leave centre of Tokyo no later than 3pm. (see http://wikitravel.org/en/Tokyo)
That gives you roughly 6 hours in Tokyo.
Depending on what you like I'd pick one of the following:
- head to Shibuya for fashion/shopping or Harajuku for a young peoples area. Wonderful energy in both of these places:
- Akihabara is the electronics district which is always quite a wonder
- Asakusa is not bad for a quick temple experience, although it doesn't rate compared to say Kamakura, which is 2.5 hours south of Tokyo.
Here is a one day itinerary, but I think you'd be knackered at the end of this:
enjoy. I always have a ball when in Tokyo
simon about 7 years ago