Tokyo is one of the largest bustling metropolises in the world. It provides limitless opportunities to its inhabitants and near limitless opportunities to tourists.
Nearby the Heian shrine, the Tokyo Sky Tree offers fantanstic bird's eye views of the city, and of course Tokyo Tower offers the same opportunity from a slightly different vantage point.
And of course, the food and nightlife options in Japan are unparalleled. The Roponggi district is a notable go-to for such things, but Tokyo is so vast and full, you'll do well no matter what district you set out to go to.