shinkansen reservation

Hello everyone,

I'll be travelling to Japan later this year, and will buy the JR East 3-day Pass when I arrive there (shouldn't be a problem if it's within the sales period?).
I want to reserve a shinkansen ticket at the same time using the pass, but I was wondering if it would be wise to leave the reservation until then (a week before using the shinkansen)? There are particular times I would like to travel at,so in that case would it perhaps be a problem?

Thanks for any constructive advice:)

During most times of the year, you have no problems getting a seat reservation, if you make the reservation just a few hours or a day in advance. Often, the trains do not book out.

Only during the peak days of some busy travel seasons, it is recommended to make seat reservations several days in advance.

The following website allows you to make seat reservations for use by the JR East Pass from abroad in English:
http://jreast-shinkansen-reservation.eki-net.com/pc/eng...