Do I have to pre-book seats?

Hi there,

With a Japan Rail Pass you are free to jump onto any valid train and use non-reserved seating. In addition to this, seat reservations are totally free for JR Pass holders and are very simple to make. If you do make a reservation and miss your train, simply make another one for a later train, or board the next train and use non-reserved seating. This flexibility is the beauty of the JR Pass!

The only thing to be aware of is that certain specialist trains (notably the Narita Express, or N'Ex) must have a seat reservation before you board, but in general all normal trains and shinkansen bullet trains have non-reserved seats for you to use.

Hope this helps!