The only qualification to this. This doesn't apply to the Nozomi or Mizuho trains. As the JR pass doesn't cover those shinks. Even though they have non reserved carriages.I've used a JR pass in the past to travel,without getting a ticket for the shink. I just wandered onto the platform via the side gates and then stood in the non reserved area on the platform.
These below are all "reserved" shinkansen. In order to ride you must go to a ticket office.
- The Hayate and Hayabusa services on the Tohoku-Hokkaido Shinkansen between Tokyo and Shin-Hakodate-Hokuto.
- The Komachi services on the Akita Shinkansen between Tokyo and Akita.
- The Kagayaki services on the Hokuriku Shinkansen between Tokyo and Kanazawa.