
Shinjuku is one of the busiest cities in Tokyo. Compared with
Shibuya, which is the other busiest city, Shinjuku is less dirty and more business-like with a number of skyscrapers.
Shinjuku Station is famous for its size. You have to specify the entrance (there are North, South, East, and West Entrance) to meet at the station.
>> Kabuki-cho
The busiest entertainment district in Shinjuku, or even in Tokyo, is Kabuki-cho. Within the 600 meters square, there are more than 4000 restaurants, entertainment and amusement centers. You'll be surprised by lots of people, neon lights, and also noises there.

Once you walk into this area, you'll keep being asked by many people. They are called "catch," and they try to catch more people to come to their shops by asking. A lot of catch stand on the street and keep talking to passengers. They often offer special price to attract people.

This area is also famous for adult-entertainment business. The business is popular not only for men but also women. There are clubs, called "host-club," where women enjoy the company of young as well as good-looking guys.
>> Lost in Translation / New York Grill
If you've seen the movie, "Lost In Translation," in which Bill Murray and Scarlett Johansson wander around Tokyo, you would identify this area. It's because the hotel they stayed at (with swimming pool) is Park Hyatt Tokyo in Shinjuku.

The bar where they met in the movie is New York Bar/Grill on the 52nd floor of the hotel. You can drop by and enjoy the drink, the music, and the sight. The cover charge is 2000 yen ($17).
View from New York Grill