Reserved seat bullet train tickets can be purchased up to 1 month in advance, at any staffed JR stations throughout the country.
Thank you for the info. Is the price the same if purchased in advance as of the day of travel?
Yes, reserved seats cost the same regardless of when you book at a JR Station.
The cost of Shinkansen is fixed, with only difference to reserved seat at peak/normal/idle seasons by around 200Y only. When you make a reservation will not differ for a given date of travel
There are advance purchase fares now available (some restrictions apply).
BTW - if you look at places like Hyperdia, they will not show the advance purchase fare options. You have to know where they are and how to get them, but certainly they now exist (as of a few months ago at least).Edited: 12 May 2018, 23:52
We traveled from Kyoto to Tokyo on the Nozomi bullet train and reserved our tickets in advance before we left the US on the app I linked above. We then went to the station the day before our trip and picked up our actual tickets at the station, but you could go just before your trip. By reserving, we were able to not only be sure we had a spot on the train, but were able to select our seat as well. When we traveled in April, the train car we traveled in was full.
The app requires you to create a password, and when you go to pick up your tickets you need to bring the credit card you used to purchase. They also said you would need the password to pick up the tickets but I don't recall needing that when we actually picked them up. It was a pretty simple process.Edited: 13 May 2018, 01:57
Notice I said price is the same at any JR station. Elsewhere, discount fares had been around for years, but not practical for most casual tourists.
Yes bibimbob, I was not disagreeing. Other people have stated there is no advance purchase discount available, but without the "at a JR station" tag. Certainly does not apply to all lines/trains, but the savings can be quite good.