Tokyo is most likely radically different from any other city you have visited and is very difficult to describe. The city, on the one hand, is state-of-the-art and a pioneer in technology, and on the other, still very much bound by the country’s old traditions. After dressing in modern fashion and adopting Western customs, Tokyo has become a center of finance and trends not only in Japan but throughout Asia.
Admittedly, it is an expensive city to holiday in, but not as expensive as Norway. Tokyo is fascinating, and constantly evolving. You will always learn something new about the city no matter how many times you visit it.
If you plan to travel around to see a bit more of Japan than just the capital, consider purchasing a Japan Rail Pass BEFORE you travel to Japan. A 7-day pass will usually be less expensive than a return ticket to Osaka or Kyoto, but these are available in several variants, depending on the duration or region.