To place an international phone call, you will need to dial your country’s exit code--the number that tells your phone service that you will be calling outside the country. If you were to place an international call from the United States, your exit code would be 011, while if calling from Argentina, you would dial 00 to call internationally. To find out what your country’s exit code is, simply run a search on your favorite internet search engine. Type in a phrase like “[The name of your country] exit code.” In this case, the country is Japan. Japan’s country code is 81. The area codes in Japan can range from one to five digits in length, depending on the area you are trying to reach. The area codes are as follows:  Akita 18 Himeji 79 Matsudo 47 Takatsuki 72 Hirakata 72 Matsuyama 89 Tokorozawa 4 Hiroshima 82 Miyazaki 985 Tokyo 3 Ichikawa 47 Nagano 26 Toyama 76 Ichinomiya 586 Nagasaki 95 Toyohashi 532 Iwaki 246 Nagoya 52 Toyonaka 6 Kagoshima 99 Naha 98 Toyota 565 Kanazawa 76 Nara 742 Utsunomiya 28 Kashiwa 4 Niigata 25 Wakayama 73 Kasugai 568 Nishinomiya 798 Yokkaichi 59 Kawagoe 49 Oita 97 Yokohama 45 Kawaguchi 48 Okayama 86 Yokosuka 46 Kawasaki 44 Okazaki 564 Amagasaki 6 Kitakyushu 93 Osaka 6 Asahikawa 166 Kobe 78 Otsu 77 Chiba 43 Kochi 88 Sagamihara 42 Fujisawa 466 Kofu 55 Saitama 48 Fukuoka 92 Koriyama 24 Sakai 72 Fukuyama 84 Kumamoto 96 Sapporo 11 Funabashi 47 Koshigaya 48 Sendai 22 Gifu 58 Kurashiki 86 Shizuoka 54 Hachioji 42 Kyoto 75 Suita 6 Hamamatsu 53 Machida 42 Takamatsu 87 Higashiosaka 6 Maebashi 27 Takasaki 27 Himeji 79 Matsudo 47 Takatsuki 72 Hirakata 72 Matsuyama 89 Tokorozawa 4 Hiroshima 82 Miyazaki 985 Tokyo 3 Ichikawa 47 Nagano 26 Toyama 76 Ichinomiya 586 Nagasaki 95 Toyohashi 532 Iwaki 246 Nagoya 52 Toyonaka 6 Kagoshima 99 Naha 98 Toyota 565 Kanazawa 76 Nara 742 Utsunomiya 28 Kashiwa 4 Niigata 25 Wakayama 73 Kasugai 568 Nishinomiya 798 Yokkaichi 59 Kawagoe 49 Oita 97 Yokohama 45 Kawaguchi 48 Okayama 86 Yokosuka 46 This is the number of the person, business, or cell phone that you are trying to...

TL;DR in Vietnamese:
Tìm mã thoát quốc tế của quốc gia bạn đang sống. Tìm mã của quốc gia bạn đang muốn gọi đến. Tìm mã vùng của người bạn đang muốn gọi đến. Cần biết số điện thoại tại nơi bạn gọi đến.