Calling Japan from the United States explained:

• 011 - US exit code; must be dialed first for all international calls made from the USA or Canada
• 81 - country code for Japan
• Area code - 1 - 5 digit codes
• phone number - 4 - 8 digits; area code + phone number total 9 digits for landlines
Example: Phone number 080-2195-1509 would be dialed as 011-81-80-2195-1509.

Area Codes:

Asahikawa 166 Kawaguchi 48 Osaka 6
Chiba 43 Kawasaki 44 Sakai 72
Fukuoka 92 Kita-Kyushu 93 Sapporo 11
Funabashi 47 Kobe 78 Sendai 22
Gifu 58 Kurashiki 86 Shimizu 543
Hachioji 42 Kyoto 75 Shizuoka 54
Hamamatsu 53 Matsudo 47 Tokyo 3
Hateruma 9808 Matsuyama 89 Toyonaka 6
Himeji 79 Nagasaki 95 Urawa 48
Hiroshima 82 Nagoya 52 Utsunomiya 28
Ichikawa City 47 Niigata 25 Wakayama 73
Kagoshima 99 Oita 97 Yokohama 45
Kanazawa 76 Okayama 86 Yokosuka 46

Dialing format for calls to a cell phone:

011 + 81 + 80 ???? ????
or 90 ???? ????