I'm always happy to offer random advice about what to see when planning a trip to Japan. While the Kansai (Kyoto-Osaka) area is frankly the best place to go for quality sightseeing, there are some nice places to visit in the Kanto (Tokyo) region, too. One of my favorites is Nikko, pretty much the most beautiful complex of temples and Japanese gardens in Eastern Japan, where you can see where Ieyasu Tokugawa's ashes are interred as well as those "see no evil, speak no evil" monkeys. Another place I like to recommend to people is Tobu World Square, conveniently located near Nikko, which is a theme park filled with super detailed miniatures, all recreated at 25:1 scale. Walking through the park you see all the most famous buildings in the U.S., including the World Trade Center standing tall, then stroll past the Pyramids and the great cathedrals of Europe, see the Long Castle of 10,000 Leagues (as the Great Wall is called) and visit all the famous temples in Japan in miniature form. You can even see a replica of the Tokyo Sky Tree, the new broadcasting tower that will stand more than 630 meters when it's completed in 2012.
I'm a fan of Tobu World Square, an amusement park of realistic miniatures.