Reservation/Seats on Tokyo/Kyoto train

Hello Daniel,

I have looked at your prior responses, but can’t find one on my particular issue.

If I purchase the JRPass in advance and receive the exchange voucher, it seems I cannot reserve a seat on a train until I arrive in Tokyo and activate and exchange the voucher for the JRPass. I have hotel reservations for each night, dinner and tour reservations all set and a group of 5 so I really need to be sure that I can take specific trains. Is it possible with the voucher to reserve a space on a particular train (even if not a particular seat on that train) in advance of arriving in Tokyo?

If I cannot do this with a JR Pass, can I do it by purchasing the tickets individually on the website? If so, can I exchange/return those individual tickets once I see that I can get the reservations I need?

I am trying to assure that I can get my group on specific trains between Tokyo and Kyoto. What is the best and least expensive way to do so?

Thank you,