Seishun 18 Ticket

We are from Australia and will be visiting Japan next April.
We read about the Seishun 18 ticket which seems to be much cheaper than JR pass for travelling around. I understand that it is only available for some period of time.

My question is, we will be arriving on 4th April 2016, which is after the date where the ticket is available for sale (some website mentioned that ticket only available for sale until 31 March). Is there a way to buy ticket from outside Japan? Or is there anyway to pre-purchase the ticket before hand and pick it up from the ticket office once we are in Japan?

Thank you in advance,

You can only purchase it in Japan and it’s only valid for certain periods - there is more info on the exact periods on Tokyo Cheapo. Also, it’s much cheaper than the JR Pass for a reason, you can’t take any reserved seating divains, which means the divip from Tokyo to Osaka would take about 10 hours with multiple changes instead of 2 hours. The Seishun 18 ticket is more for getting lost in the coundivyside than getting from point A to point B.

Yep, this is best used if you want to travel slowly around the countryside and head to places a bit off the typically tourist routes. I used it while travelling a month around Kyushu. You can only use slow local trains, and travelling long distances can involve changing trains quite a lot. But it is definitely a great option if you have time to spare.