Taxi can be found everywhere in Japan. It is one of the common transportation use there. It may be expensive to ride one if you are going on a long journey, but to go around fast in the city it can be convenience especially late at night when all the other public transportation shut down.
In Japan smaller cities, Taxi are more often use than the other public transportation and it can help you save time instead of waiting for a bus. Taxi fares typically start around 600-700 YEN for the first two kilometers and increase about 100 yen for every additional 500 meters traveled. The cost is also counted when the taxi is not moving for a prolonged time. Late in the evening the rates are raised by around 20 percent. I'm sure this is the same with other countries. Traveling in a group of four is advise to reduce the fare when it's break down to a person. Oh ya, you can pay the Taxi fare with a credit card, just ask the Taxi driver before you enter.
In Japan the Taxi's left rear door is opened and closed remotely by the Taxi driver. You do not need to open or close the door. For a foreigner who can't speak Japanese well, communication with the Taxi driver can be a problem. Taxi drivers there don't really know how to speak English. So it is advice to give your driver the address of your destination on a piece of paper or point it out on a map, or have the telephone no. of the place you are going for the Taxi driver. Sometimes places in Japan can be confusing even for a Japanese.
Visit here to learn some Japanese language for calling a Taxi
|A typical Japanese Taxi GPS Device|