Some of you are very nervous of language barrier. But in 2014, more than 13 million tourists have visited Japan. I believe 99% of tourists did not understand Japanese. But most of tourist have completed their travel without a huge issue. It is not very hard to make a trip to Japan without speaking Japanese. I think the signage and the announcement in both station and train help travellers and take them to the right direction.
When you take Shinkansen or Limited Express train, you may book a seat and some trains require you a seat reservation. Though some of the express train have a non-reserved seat, you should book a reserved seat if you can. If you use JR Pass, Hokkaido Rail Pass, JR East Pass, Tokyo Wide Pass, Sanyo San’in Area Pass and Kyushu Area Pass, these passes cover a reserved seat fee. You should use this benefit. And also I strongly recommend to secure your seat especially in the peak seasons, such as late April to the first week of May (a.k.a. Golden Week), August 10 to 20 (It is called “Obon” which is a summer break.) and December 29 to the first week of January.