If I wish to book a seat on a train from,say, Sendai to Tokyo, do I need to make the booking before the train has left its original station at Shin-Aomori, or can the seat be reserved at any time up to actual departure from Sendai.
I might wish to do the same with a train from Hiroshima to Osaka. Can I book the seat any time up to departure from Hiroshima, or do I have to book it before the train has left its original start station, which may be 2 or 3 hours beforehand ?
I will have a Japan Rail Pass for the Green Car, for which I believe reservations are mandatory ?
Thank you in anticipation.