Thanks guys. That solves my question for this specific journey, but I'm still wondering in a more general sense, when you transfer from JR to private lines, or vice versa, at what point do you pay for your second leg?
This happens all the time in Tokyo. A subway train can turn into a private regional train after a certain point. You don't even need to switch trains, the train itself changes. If I don't have a pass, I just buy a ticket that goes all the way through at the start. If I do have a pass, I pay at the other end. There are the add a fare machines or you can just go up to the dude manning the gate.
