Tokyo

     Tokyo is Japan's capital and the world's most populous metropolis. It is also one of Japan's 47 prefectures, consisting of 23 central city wards and multiple cities, towns and villages west of the city center. 

Tokyo Imperial Palace

     

     The current Imperial Palace is located on the former site of Edo Castle, a large park area surrounded by moats and massive stone walls in the center of Tokyo, a short walk fromTokyo Station. It is the residence of Japan's Imperial Family.

Yurakucho

 

     The Yurakucho (有楽町, Yūrakuchō) district lies one stop south of Tokyo Station along the JR Yamanote Line. Yurakucho offers a wealth of shopping and dining opportunities. Yet at the same time, Yurakucho has a more approachable, relaxed atmosphere than its upscale neighbor, and parts of it maintain a charming, old neighborhood feel.

     One of Yurakucho's most interesting draws is the lively restaurant district built up under the brick arches beneath the elevated train tracks of the JR Yamanote Line. Known in Japanese as Gado-shita, from "below the girder", these favored watering holes of Tokyo businessmen occupy virtually all of the free space under nearly 700 meters of track on both sides of Yurakucho Station.

Marunouchi
 

     Located between the Imperial Palace and Tokyo Station, Marunouchi is one of Japan's most prestigious business districts. During the Edo Period, Marunouchi (literally "within the enclosure") was located within the outer moats of Edo Castle and contained the residences of some of Japan's most powerful feudal lords. Together with neighboring Otemachi, Marunouchi is now home to the headquarters of many of Japan's most powerful companies, particularly from the financial sector.

My opinion:
     Tokyo is an amazingly large place and always crowded, but it can be a lot of fun. And it’s have many place that you can go.
     First is Imperial Palace. It is very serious place where you can look but not really touch. The Emperor of Japan and his family live here and they are considered to be the direct descendants of the Japanese sun-goddess     
     Second is Yurakucho. It is surrounded by a huge number of restaurants, both international as well as local food. Many of the restaurants are very small and many do not have English menus. However, you can eat like locals here.
     The last one is Marunouchi. It is the walls Street in Japan. Most of the Big company and International Bank may have their head office here. If you find hotel It has a lot for of you.