The Japan Rail Pass is one of the economical ways of getting around Japan for travellers. The pass allows unlimited travel on all JR trains including the "bullet train", or Shinkansen, in Japanese.
It is basically only available for people coming to Japan on a tourist visa and Japanese citizens who are living abroad.
Passes need to be bought in your home country. You can also purchase a rail pass online. 7, 14 and 21 day passes are available starting from 28,000 yen for 7 days. A one way trip from Tokyo to Osaka costs approximately 13,000 yen.
It is not necessary to validate the ticket as soon as you arrive in Japan. Tokyo has many private railways which the pass is not valid on. If you are planning to stay in Tokyo for a period of time, it might be more economical to not valid your pass straight away.
The bullet train gets booked very quickly especially during holiday periods, so it is probably a good idea to try and book a seat. You can book seats at most major JR stations. Look for the reservation office or "midori-madoguchi" (green-window) in Japanese. You may need to show your passport when you validate your ticket or when you are on a train.
The busiest times which Japanese travel are as follows: December 28 to January 6 (New Year's holiday), April 27 to May 6 (Golden week) and August 11 to 20 (Obon holiday).
