Choose a line before the flight or at the airport
KDDI's povo Japan SIM is a data-only eSIM for international visitors. KDDI says the application and profile download can be completed online while still abroad, so an eSIM-capable, unlocked phone can be prepared before the flight. Its 2026 announcement says the package is bought as a data topping. It does not provide ordinary voice calling; keep a way to reach hotels or transport providers.
A physical SIM remains a practical alternative. SoftBank's Prepaid SIM for Travel is sold through SoftBank shops, electronics retailers and airport rental counters. Narita Airport lists SIM sales and vending machines in Terminals 1 and 2, including machines on arrivals floors. The listed sales points are before departure passport control.
What KDDI's current visitor eSIM offers
KDDI revised the online Japan SIM range in March 2026. At the time of checking, its published list included 3 GB for three days at ¥600, 5 GB for five days at ¥900, 10 GB for seven days at ¥1,430 and 20 GB for 30 days at ¥2,700. The same announcement describes timed unlimited options: three, five or seven days, each paired with an immediately issued 0.5 GB allowance lasting 60 days. For the timed options, KDDI says a promotion code lets the traveller choose when to start the unlimited period. Check when each allowance starts if buying before arrival.
The March notice also says several older toppings were discontinued, including the former 1 GB three-day option and some short unlimited passes. It explicitly distinguishes the online lineup from Japan SIM sold through Lawson stores. Check the live checkout before paying. KDDI warns that speeds may be restricted during congestion.
Passport, handset and activation checks
SoftBank sets specific conditions for its visitor SIM: the buyer must be at least 18, the phone must be SIM-lock-free, and activation requires a camera phone and a photograph of the original passport. Its instructions say to insert the card, configure the access point name if needed, and register through its visitor website. SoftBank says service should become available within about 30 minutes after the application is processed, but it may reject an application under its criteria. Allow time for registration at the airport.
SoftBank describes its product as a 4G data SIM and lists LTE bands 1, 3, 8 and 41 for device compatibility. It says the retail sale price is set by the retailer. Its page still shows a 500 MB additional plan price but says applications for it stopped in February 2025. KDDI's online visitor eSIM follows a different download process. The tourism board's SIM guidance says a handset should be SIM-free and bear the technical standards conformity symbol for specified wireless equipment. Check the handset's lock, eSIM and band specifications before buying.
Check coverage on the route, not just in Tokyo
NTT Docomo publishes separate service-area searches for 5G and 4G LTE. SoftBank also directs customers to a model-specific service-area view and cautions that reception can vary with the handset, contract and conditions even inside a mapped area. Use the maps for mountain roads, islands and rural stops. Look up each destination and the journey between them on the network that the chosen plan actually uses. SoftBank labels its visitor SIM as 4G.
The national tourism board says hotspots are common in larger cities but recommends checking whether smaller rural accommodation has Wi-Fi. Save the accommodation address and an offline map. If the route includes several distant regions, compare the carrier's 4G area first; 5G should be treated as an extra where its map shows service. Confirm the home carrier's Japan roaming charges. Docomo's international-service page describes roaming for its own customers travelling abroad, not a visitor price for a foreign SIM in Japan.
Connections at Narita and on the rail network
Narita Airport says free Wi-Fi reaches every terminal and its terminal shuttle buses. Select FreeWiFi-NARITA and accept the connection terms; the airport warns that congestion can affect performance. Save eSIM instructions before boarding in case the network is busy.
For a long train journey, JR Central says Shinkansen_Free_Wi-Fi is available on all Tokaido, Sanyo and Kyushu Shinkansen trains; access uses an email address or social account and requires a new login every 30 minutes. It also lists service near ticket gates at Tokaido Shinkansen stations such as Tokyo, Nagoya, Kyoto and Shin-Osaka. Keep key tickets available offline. JR East's Welcome Suica Mobile app, aimed at overseas visitors, links to reservations for services including the Narita Express and several eastern Shinkansen routes. Set up the app while connected.
Keep a voice route for emergencies
Japan's emergency numbers are 110 for police and 119 for fire or ambulance, according to the national tourism board. It also runs the Japan Visitor Hotline at 050-3816-2787 around the clock for help with accidents, illness, natural disasters and general visitor questions in English, Chinese and Korean. Save these numbers and the first hotel's address.
SoftBank calls its visitor SIM data-only, and KDDI calls Japan SIM a data-only eSIM. Neither operator page confirms that those products can place an ordinary emergency call. Do not rely on a data-only line as the sole way to ring 110 or 119. A voice-capable home line with roaming, another phone, or help from a staffed station or hotel provides a clearer fallback. Check the home carrier's Japan voice and roaming terms before departure.
Set up both lines before travelling
On a compatible iPhone, Apple says a travel eSIM can run beside a home line and that the user can choose which line carries mobile data. Download the Japan profile over reliable Wi-Fi, label both lines, and set the intended travel line for data when it is ready to use. Keeping the home line on can retain its usual functions, but Apple warns that it may still incur roaming fees. Check home-carrier charges and settings before landing. Keep the home number available for calls or verification texts.
A physical SoftBank card instead needs a free SIM slot and its registration and access-point steps after insertion. If the phone has one physical slot already occupied, check whether the home line can be moved to eSIM before buying a physical Japan card. Test a browser page and map after switching lines; keep tickets offline. For a comparison of travel data options, consult our Japan plan page alongside the operator coverage maps.
Networks our Japan plans use
These are the operators named on our plans for Japan, taken from the plan data, so the list follows the catalogue.
- KDDI5G
- KDDI/au5G
- NTT docomo5G
- Rakuten Mobile5G
- Softbank5G
- SoftBank5G
- SoftBank Corp.5G