Bonjour Delmas, I’d recommend the nationwide Japan Rail Pass.
It can be purchased as standard or green, where green is more of a business seat wagon.
However, both pass types include the same lines and trains. It’s only a matter of seat classes when on the train itself.

There are something called regional pass, but I’d say you benefit more from a Nation wide as your destination includes many different areas.

You can purchase your Japan Rail Pass from here: https://getjrpass.com/order-jrpass/

Please let me know if there’s anything else I can do to help and have a wonderful stay in Japan! 😊

With kinds regards, Jonathan H.
Getjrpass.com staff