A Nationwide Japan Rail Pass allows you to board on the majority of trains that run on the JR railway network, including regional routes such as JR Kyushu, JR East, JR West, JR Central, JR Shikoku and JR Hokkaido. You will have access to local and express trains, fast bullet trains, and the 'Shinkansen' on the Hikari or Sakura lines.
The Japan Rail Pass is not valid for: Private Rail Lines, Super Express-Only Shinkansen trains 'Nozomi' and 'Mizuho', subways or trams within cities, sleeper wagons/ private wagons in night trains, and special compartments for which you will have to pay an extra fee.
If the JR train uses non-JR tracks during its route, additional fares may be required for that part of the trip. Payment is done either before boarding or after boarding the train.