Read up on Tokyo Before You Visit
If you are planning a trip to Tokyo you will be well served to purchase a good guidebook or create your own Frankenguide, a personalized guidebook that you create by locating information from a variety of sources, both online and in print. This will help you flush out your itinerary but another, often overlooked tool, to help you make the most out of your trip is to read books about the history and culture of your destination. Some great books have been written about Tokyo, and they are engaging stories about families or institutions in Japan that will really enhance your visit by providing you with a deeper understanding of the place and its people. Here are just a few examples of interesting books that I have read over the years and would recommend:
The Commoner - A fictional account of the life of a commoner who marries into the Japanese Royal family that is based on the real lives of Empress Michiko and Princess Masako of Japan.
Tokyo Underworld: The Fast Times and Hard Life of an American Gangster in Japan - A well researched true story of the mob in Japan that starts before WWII and ends in the 1990's. You will never think of Roppongi as just a cool place where foreigners hang out to party after reading this engaging story.
Memoirs of a Geisha - This well known fictional book, and movie, offers insight into the life of a Geisha from her days as a Maiko, or trainee, right through to her retirement.
The Brothers: The Hidden World of Japan's Richest Family - The multi generational tale of how the Seibu Family built a rail, hotel, and retail empire in Japan. Based primarily in Tokyo this book offers great insight into how business is done in Japan, the intricacies of family life and the constraints of societal rules in Japan.
All of these books are fact based or true tales of a certain aspect of life in Japan and reading one or more of them before you travel will add a lot of depth and understanding to your experience of Tokyo.