Reserved & Non-Reserved Seating

Hello Daniel,

When we arrive at Narita and exchange our JR voucher, are we allowed to reserve our seats for the week? Is reserved seating only in Shinkansen and Express trains?

If we purchase the Ordinary Class: Are the reserved and non-reserved seating in separate carriages? Is there an additional charge to reserve seating?

If we purchase the Green Class: In order to ride in the Green Class carriages, do we need to have reserve seating for all trains/buses or just shinkansen and express trains?

Thank you for your assistance!

Sincerely,
Mary