In Japan, different train types have different seat classes. In general, most trains offer two classes of seats: ordinary seat and green car seat. Green car can be considered first class. A few shinkansen trains have a Gran Class available, which is the ultimate luxurious class.
Ordinary seats are the most common and can be found on all trains in Japan. Different level of trains, or trains that operated by different operators, have different layout of ordinary class. But they are all comfortable, clean and have sufficient leg room.
On shinkansen trains, ordinary seats are arranged as 3+2 across the carriage width. While on trains that other than shinkansen, e.g. limited express and express, ordinary seats are arranged as 2+2 across the carriage width.
Ordinary class on shinkansen trains and limited express trains have reserved cars and unreserved cars. Thus ticket for ordinary class are sold as reserved or unreserved.
A reserved seat on ordinary class comes with an allocated seat. A reserved ticket fee will be added to the basic ticket fare. Seats need to be reserved in advance at a JR ticket office before boarding.
An unreserved seat on ordinary class doesn’t have an allocated seat. You can sit on at any available seats you like. Tickets on unreserved cars have unlimited number. In most cases you can find a seat on the unreserved car easily. But during peak travel seasons like Spring Break (late March to early April), Golden Week (April 28th to May 6th) and New Year (December 29 to January 2nd), you may find that all seats are taken and you will have to stand for your whole train journey.
Green car is equivalent to first class in Japan. You can identify the green car by the symbol of clover next to the door. The green car seating is more spacious, with more leg and elbow room. There are four seats (2+2) in a row on shinkansen trains, and 3 seats (2+1) in a row on limited express trains.
The green car gives you a more comfortable train travel experience. The seats are softer and can be reclined up to 40 degrees. Green cars are always quiet, even during peak seasons and holidays.
Green car seats are expensive than ordinary seats. All green car seats are reserved. Seats can be reserved a month prior to departure.
Shinkansen trains and some limited express trains have green cars available.
Gran Class is first introduced in Tohoku Shinkansen between Tokyo and Aomori in 2011. It is the most luxurious class of seat on Japanese trains. There are three seats in a row arranged as 2+1 (two seats on one side and one on the other side of the aisle). In total 6 rows in each gran car.
Gran cars are well-equipped with the latest technology. The interior decoration of the gran car is extremely gorgeous. Each gran car has a dedicated attendant who can be called to your seat with a button on your armrest. Food and soft drinks are included in the ticket fare.
Not all the shinkansen trains provide gran class. But in the future, more trains with gran class will be introduced to the Japanese rail network.
Shinkansen is Japan's high-speed train (bullet train), with maximum speeds of 240–320 kph (149–198 mph).
If you plan to take trains in Japan, JR Pass is an incredibly good value for money and can save you a lot of hassle.