If you are planning a trip to Japan then you may want to try fitting in a visit to Osaka which is located roughly around the middle of Japan. We took a bullet train and got to Osaka from Tokyo in about 3 hours.
Despite rain for the two days that we were in Osaka last weekend, the bright colors and gorgeous store fronts are more than enough to help you forget about the rain. Osaka was hardly affected by the Tohoku Kanto Earthquake so there isn't really a movement or need to save electricity on this end of Japan which means that the place is generally much brighter than Tokyo.
Namba is the area that you'll want to explore when you reach Osaka which is home to the Shinsaibashi indoor shopping mall which is just shy of 600 meters long. Also in Namba is Dotonbori - a river which runs through Osaka that is filled with restaurants in the surrounding area. And then there is Otaroad (the equivalent of Akihabara) just around the corner which has stores like the most fab Gamers.
First thing to do is get off at Namba station . Google Maps localize the reading to "Nanba" however.