Gran Class Shinkansen questions

Hello, I have a trip in winter 2019 and I want to try the Gran Class out once during it. I know the Green car JR pass does not cover it fully, only about a quarter of it is covered, but how do we buy the gran class ticket with out JR Green Pass as a reduced fee?

Also, I will be doing it on Day one of my 21 Day JR Green Pass so I won't be able to reserve it at Japan. Is it possible to reserve ahead of time from the US? If it is possible, what is the earliest we can reserve? I plan on going from Shin-Hakodate to Tokyo Station.

If we can't reserve, what is the likelihood of being able to land a seat at the station on the day I receive my pass? The day is on December 27, 2019.

Just pay the difference when booking tickets.

Seats can be reserved one month out using jr east website.

New years period is very busy.

Just pay the difference when booking tickets.

No, you must pay the GranClass surcharge in full, not just the difference with the Green one.

Concretely, just buy a GranClass limited express ticket exactly as if you did not have a pass. No need to buy a base fare ticket; the pass covers that.

Too early.
There is no guarantee that the PASS rules doesn't change.
Any special discount ticket is not permanent one.

The current rules are written in pass official web.
http://www.japanrailpass.net/en/about_jrp.html#bm_003

Oh, right, I had missed the 2019 part... If that's not a typo, move on and come back in 2 years; no point discussing anything, let alone ticketing minutia, now.

Concretely, just buy a GranClass limited express ticket exactly as if you did not have a pass. No need to buy a base fare ticket; the pass covers that.

So pay the difference the pass does not cover???

Thanks for the info. I'll check up in two years.

But with the current news, the base fare is covered by the JR Green Pass. Do we go to the reservation to buy the Gran Class ticket and receive the base fare ticket?

Thanks for the info everybody

Do we go to the reservation to buy the Gran Class ticket and receive the base fare ticket?

You get a ticket for the shinkansen supplement fee (tokkyuken) for a Gran Car seat, while the rail pass serves as your base fare ticket.

Some basics about Japanese train tickets are found here:
http://www.japan-guide.com/e/e2359_001.html

So pay the difference the pass does not cover???

Well, I suppose it depends what you mean by "difference"... Many people incorrectly think that you would need to pay the difference between the price of a GranClass ticket (26,720 yen) and that of a Green one (18,500 yen), which would amount to 8,220 yen. But in fact you must pay the full 26,720 yen for a GranClass seat.