If you have a time to travel around Japan, Seisyun 18 is the cheapest JR ticket in this season.
(Actually, it offers 3 times per year like spring, summer, winter.)
This is the explain for Seisyun 18 from East Japan Railway Company.
Also, you can check the HP.
1. What is is?
The Seishun 18 is a limited-time offer. Please take note of the sales and valid dates.
The Seishun 18 allows unlimited rides on local and rapid JR trains (excluding reserved seats) throughout Japan from Hokkaido in the north to Kyushu in the south. Although the Seishun 18 is not valid on Shinkansens and limited express trains, it is a great way to enjoy travel at a more leisurely pace. This ticket package includes five days worth of travel for only 2,300 yen per day. One person can enjoy the Seishun 18 for five days, or it can be split for use by up to five people. The unlimited rides also include use of the JR Miyajima Ferry for travel from the mainland to the island of Itsukushima, popularly known as Miyajima. The Seishun 18 is a great way to enjoy leisurely travel.
Note: The price for the Seishun 18 is the same for adults and children.
3. Valid Periods and Sales Dates
Friday, July 20 to Monday, September 10, 2012
Sunday, July 1 to Friday, August 31, 2012
Monday, December 10 to Thursday, January 10, 2013
Saturday, December 1 to Monday, December 31, 2012
The five days of travel can be shared by two or more people, though if the ticket is used by more than one person at one time, those people must be traveling together. Each day one person uses the Seishun 18 counts as one day of travel. Therefore, if five people use the ticket on the same day, the ticket will be used up at the end of that day.
The period of one day begins at midnight and ends at 23:59 that night. If traveling on a train at 23:59 at the end of a day of travel, the valid period of the ticket is extended until the next stop.
Using the Seishun 18 – Present the ticket at the station or on the train. A station or train staff will stamp it with that day’s date. The Seishun 18 cannot be used in automatic ticket gate machines.
5. Valid Train RoutesUnlimited rides on local and rapid trains (excluding reserved seats) within the designated open seating zone on the following transportation services: All JR company lines throughout Japan - JR Hokkaido, JR East, JR Central, JR West, JR Shikoku and JR Kyushu
The JR West Miyajima Ferry
Even in combination with a Super (Limited) Express Seat or other special ticket, the Seishun 18 cannot be used for travel on Shinkansens, limited express trains, express trains or sleeper cars.
Note: The area within the dotted line in the map below is where the Aoimori Railway operates. The Seishun 18 is valid on local and rapid trains between Aomori and Hachinohe Stations. Riders may get off at Noheji Station free of charge, but an additional fare is required to get off at any other station between Aomori and Hachinohe Stations.
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