The Ticket Display

Above the front window / close to driver’s seat is a big display.
There is a ‘dynamic sign’, meaning it changes the display over time as you go.
You locate your number (printed on the ticket) in the designated ‘slot’, and that number has a fee displayed right next to ir, or under it,
This will then increases the longer you ride the bus.
The further you ride, the more your cost will increase,
but you will also notice new zones being added from the start, pushing ‘your zone’ to the right, all while the price goes up.
Pretty easy to follow and you will know exactly hoe much you must pay exiting the bus at any stop.
By the way this system is also in place on some local train lines. I have seen it in operation for ex on the Minobu line in Yamashi prefecture.