There are several kinds of public telephones (koshu denwa) in Japan. Most are green and take phone cards that can be bought for 500yen, 1,000yen, 5,000yen, and 10,000yen from vending machines, station kiosks, and department stores. It is a good idea to keep one in your wallet or purse since they are convenient when you do not have proper change. To use a public telephone card, just pick up the receiver and push the card in the appropriate slot. A number will light up showing the remaining credits. When the credit reaches zero, you will hear a couple of beeps warning you that you are about to be disconnected. Phones with gold plates accept public telephones cards and are capable of making international calls.
Not all Japan public telephones take phone cards. If the phone is green but has not slot for a card, use 100yen and 10yen coins. The phone will not give you change for 100yen, even if you only make a 10yen call. Carry a handful of 10yen, coins so you do not waste change.
Pink phones are located inside restaurants and stores and are solely for local calls (you can not even reach the 114 directory assistance number from these phones). These phones only take 10yen coins.