Phone calls from Japan: How to save money Edit
Calling from home on a land line or from your mobile phone in Japan can be very expensive. Rates may vary depending on the time of day that you call also. The two major phone companies in Japan are KDDI and NTT, with your major mobile providers being NTT Docomo, AU, and Softbank. While they offer various special plans that can save you money some of the time, it's easier to use online services or a discount telephone service with 24-hour flat rates so you can call anytime.
Skype, LINE, and other online or messaging appsEdit
Skype is a free-to-join service that offers free calls. Installing the Skype program on your computer allows you to call other Skype users for free. It also allows you to make international calls (to land lines and mobile phones) and send SMS messages at a low rate using preloaded funds, though it should be noted that the phone number it sends from is complete nonsense (so include you name in any texts or introduce yourself really quick).
LINE is a free-to-join messaging app that has become very popular among Japanese smartphone users. Like Skype, in addition to messaging, you can load funds into the app and use them to make international calls.
SImilarly, you can use other messaging, Voice Over IP, or video conferancing apps to accomplish the same. FaceTime is very popular, but is limited to only Apple users.
Cheap calls on mobile phones Edit
Current as of 2015, NTT Docomo, AU, and Softbank all have available unlimited domestic calling within Japan and regardless of carrier (mobile or land), making Japan-to-Japan calls a non-issue. However, other plans may be available with few to no calling time offered, and the offerings of virtual mobile network operators (or MVNOs) can still vary. If you expect to use your phone for voice calls instead of just messaging and data, it's fairly simple to get one of these unlimited plans.
Unless you use a prepaid mobile phone, which means higher rates all round and is not recommended unless you can't get a regular mobile for some reason, your mobile will necessarily come with some sort of monthly calling plan. The trick here is to register for the cheapest calling plan and use another company for most of your phone calls. The calling plan will definitely have some advantages, so it's worthwhile to read the details carefully and use whatever free minutes or cheap time periods there are. Otherwise you can make calls with other discount telephone service providers on your mobile phone and pay less, and you don't have to pay your mobile company for those calls.
Discount mobile phone services in Japan (see below) usually require registration before you can make phone calls, but it's generally free. When you register you list the phone numbers of your phones - the numbers you call from - and then you can make calls on those phones to any other numbers at the rates offered by the discount phone companies.
Cheap calls on land lines Edit
The same advice as for mobiles above applies to land lines: get a line, get a cheap monthly plan (you may not have to have any plan on a land line), and use a cheap calling service for your actual calls. The best services have short prefixes for dialling, free montly statements, and automatic billing. Billing is done to your credit card or by direct debit of your bank account. If you pay by credit card you don't need a Japanese credit card; your credit card from home should be fine.
International calling, calling in Japan Edit
Current as of 2015, mobile phone plans don't (at least from the onset) contain any internation calling provisions. While such a plan could be available, the costs are likely to be quite prohibitive.
Discount mobile phone services (see below) don't only save you money on international calls. As many JETs discover quickly, local and long distance calls in Japan can be expensive too, so look around for good deals on domestic calling services. These days many discount companies offer both international and domestic service, which is good news for saving money on your mobile! Depending on which company you choose, you should be able to use the same company for calling in Japan and international calling too, both on your mobile and home phone.
Discount mobile phone services Edit
Here are links to a few discount calling services. You might also try a Google search for discount telephone in Japan or in Japanese for 格安国際電話: