Mobile Networks in Japan

Japan has four mobile networks of its own: NTT Docomo, au (run by KDDI), SoftBank and Rakuten Mobile. Coverage is strong on all of them, including inside subway tunnels and in rural valleys. All 3G service has now closed. Docomo's FOMA network was the last, ending on 31 March 2026, so every line runs on 4G or 5G.

NTT Docomo is the largest and has the widest coverage, so it is the default choice outside the main cities. au and SoftBank are close behind. Rakuten Mobile is the newer fourth network. It has roamed on au's network where its own coverage is thin. That agreement ran to 30 September 2026. Rakuten says roaming continues after that where its own network is not yet strong enough, and shrinks elsewhere, so check its coverage map for your area.

The big three each have an online plan and a cheaper second brand. ahamo runs on Docomo, povo on au and LINEMO on SoftBank, all set up in an app. UQ mobile uses au and Y!mobile uses SoftBank. IIJmio, BIGLOBE and mineo are MVNOs that rent network access from the big three. mineo sells plans on all of them, with a different APN for each.

Same masts, different APN

A brand on the same network does not always share its parent's APN. Docomo and ahamo both use spmode.ne.jp, with no username or password. SoftBank's own SIMs use plus.4g, while Y!mobile and LINEMO use plus.acs.jp.v6. Most phones bought from a network set the APN themselves, so you mainly need it for an unlocked or imported phone. Each page below lists the values.

What to pick, and a warning

For coverage everywhere, Docomo or an ahamo plan on it is the safe bet. For value in cities, the online brands are the smart choice, and povo's pay-as-you-go "toppings" suit uneven usage.

Visitors should know that Japan restricts who can buy a regular postpaid SIM. It usually asks for residency and a Japanese bank account or credit card, so tourists generally cannot sign up for a normal plan. A prepaid data SIM or a travel eSIM bought before or on arrival is almost always the right call for a short trip.

eSIM and connectivity

The networks and online brands support eSIM on compatible phones. eSIM is the easiest route for visitors because it skips the residency and paperwork of a contract SIM.

Each network page below has the APN settings and activation steps.