Tokyo is in Japanese area code 03, which is +81 3 in international format.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)
The country code and area code of Akiruno- Tokyo, Japan is 81, (0)42.
The country code and area code of Fuchu- Tokyo, Japan is 81, (0)423.
The country code and area code of Hachioji- Tokyo, Japan is 81, (0)426.
The country code and area code of Ogasawara- Tokyo, Japan is 81, (0)4998.
The country code and area code of Aichi, Japan is 81, (0)52.
The country code and area code of Daito- Osaka, Japan is 81, (0)72.
The country code and area code of Gifu, Japan is 81, (0)58.
The country code and area code of Mie, Japan is 81, (0)593.
The country code and area code of Fujisawa- Kanagawa, Japan is 81, (0)466.
The country code and area code of Atami- Shizuoka, Japan is 81, (0)557.
The country code and area code of Hitachi- Ibaraki, Japan is 81, (0)294.
The country code and area code of Aomori, Japan is 81, (0)172.