In Tokyo, Osaka and some other large cities, buses are a common means of public transportation, complementing the subway networks. In cities with less extensive train networks, such as Kyoto, buses are the primary means of public transportation.
How to use a bus
Using buses in Japan can initially appear intimidating because there are usually fewer English displays or announcements, and there are different systems of ticketing depending on the company. Here is a description of the most common system:
1) Enter the bus through the back door (or front door if there is only one door).
2) When entering, pick up a ticket from a small machine. A number is printed on the ticket, which you will later use to work out your fare.
3) A display above the driver shows the next stop and the fares for that stop in yen. To determine your fare, match the number on your ticket with the number and fare on the display.
4) When your stop is approaching, press one of the buttons on the wall to signal the driver that you wish to get off at the next stop.
5) If you do not have the exact fare, use the change machine to get small coins.
6) When getting off, put your ticket and the exact fare into the box next to the driver.
In many cities, for example in central Kyoto, a flat fare applies, i.e. you always pay the same price regardless of how far you travel. This means that you do not have to worry about steps 2) and 3) in the above description.
Of course, there are a few exceptions to the above outlined system. The most prominent exception are the Tokyo Metropolitan Buses, where you are supposed to enter through the front door, pay a flat fare when entering, and exit through the rear door.