Have you ever had a difficulty in finding out how much the train fare is?
If so or if you are in a hurry, why don't you buying the cheapest ticket first?
Next, you need to find the machine as below just before getting out of a ticket gate.
The picture abouve is from http://trns.homeip.net/SubEquipment/Sect1.html.
Don't worry, it (fare adjustment machine) is located near ticket gates and you can find it easily.



informative post, raises intrigueing points
Thank you for your comment. It's encouraging.
Why don't you try if you have a chance to come to Japan?