buses in kyoto are operated by a single driver, so you board from the rear, and alight from the front exit next to the driver, which is when you pay for your ride.
when you board the bus, you either 1) collect a paper chit from a ticket dispenser machine as you climb up the steps. It is usually on the right hand side as you get on. The paper ticket has a red number printed on it that says which bus stop you got on or 2) tap your IC card (pasmo, icoca, suica, etc) on the card reader which is usually next to the ticket dispenser. In this case, you do not need to collect a ticket from the dispenser.
when you want to get down, you have to press the bell to alert the driver. But do not get up from your seat if you are seated, and do not move to the front either. Passengers are not supposed to walk about the bus when it is moving. The bus driver will wait for you to alight so do not rush.
If you are paying cash, there is a machine next to the driver near the door for this. You are supposed to drop your coins and the paper ticket into the machine which has a clear plastic hood on top. Check how much you have to pay by looking at the large LED screen in front of the bus, looking for the fare that correspond to the number on your ticket. However, most buses travelling in the city centre area in Kyoto has a fixed fare (230 yen) so it doesn't matter so much. And these buses usually do not issue tickets when you board the bus either. If you have tapped your IC card when you got on the bus, now is the time to tap the card again on a reader next to the plastic hood where you drop your coins.
If you have insufficient coins, there is a coin changer by the side of the machine which accepts 1000 yen notes only. If you have even bigger notes, you have to change it with the bus driver.
