Campsite phone reservation

Hello,

We rented a camper van from what I would consider to be a luxury service. One of the campsites we would like to visit requires reservations by phone only. The rental service will not assist with booking because it is not apart of their license? I’ve had no issues asking hotel staff to book reservations for restaurants and other activities but I understand this is a different situation.

Can anyone shed some light on the situation? Would a kind Japanese speaking person be able to help us with the reservation? Can provide more details for booking, thanks in advance!

by Accurate-Mortgage-57