Matsumoto using Kanto Pass

Hello everyone,

I am currently planning my trip to Kanto region in April, and will surely buy a JR Kanto Pass. During the three days of its validity, I would like to go and see Matsumoto castle.

I know the Kanto pass is only valid to Kobuchizawa, so my question is :
- Do I have to get off the train at that station, buy a ticket for the remaining trip, and get on the next train ?
- Or can I just buy the ticket fot Kobuchizawa - Matsumoto in Tokyo, and stay on the train (in the unreserved seat area) ? In this case the ticket would not be validated at the entry gate, is this not a problem ?

Thank you for your help, and more generally for this wonderful website !

If you can specify your train, you can buy the ticket at any JR Ticket counter.

or you can ride the train with JR Kanto Pass, and buy the ticket between Kobuchizawa and Matsumoto from the train conductor.

Fare is the same.

I was not sure I could buy the ticket directly in the train, if I am not sure of my schedule in advance.

Thank you very much for your answer !