Look in the classified ads in newspapers for such sales. Note that you will be liable for any unpaid bills on the line you purchase. Renting a cellular phone is another option to consider. NTT has introduced a number of optional services, such as touch-tone lines, call waiting, and credit calls, allowing you to call from anywhere in Japan and have the charges included in your monthly bill. Monthly charges range from 100 to 390.
Cellular phones have a wide range and can be used while moving.
Some can call anywhere in the world via satellite. In comparison, you should be stationary when using a PHS, but they can be used underground as long as there is an antenna. Their rates are much lower than those for cellular phones. Applications for both types of phones are handled at electric appliance stores and camera shops. There is an Eastern Japan Directory and a Western Japan Directory.