Japan used emergency roaming after the Kumamoto earthquake: what visitors can use

August 10, 2026. Japan's mobile operators activated their new cross-carrier emergency network after the late-July Kumamoto earthquake disrupted service. On compatible phones, the full-roaming mode could replace an unavailable home network with another Japanese carrier's 4G LTE service for calls, SMS and data capped at 300kbps.

The system is called JAPAN Roaming, and a connected phone may show JPN-ROAM or JpnRoam. It is not ordinary international roaming and it is not active all the time. The Kumamoto activation ended as operators restored their networks on July 30.

The traveler decision: do not choose a travel plan because you expect access to JPN-ROAM. The published rules cover customers of participating Japanese carriers and eligible domestic MVNOs. We found no official promise that a foreign roaming line or Roaming eSIM profile can use it. For a fallback open to visitors, learn how to find 00000JAPAN emergency Wi-Fi and install Japan's multilingual Safety Tips app before the trip.

What happened after the Kumamoto earthquake

The earthquake caused power and transmission failures that made mobile service unavailable or difficult to use in parts of Kumamoto Prefecture. SoftBank's July 29 notice named affected areas and warned that voice calls, emergency calls and data were disrupted for SoftBank, Y!mobile, LINEMO and some MVNO users.

Operators responded with restoration work, free emergency Wi-Fi and JAPAN Roaming. Reports on July 28 and 29 documented full-roaming access for affected Docomo, KDDI and Rakuten users. The wider emergency service is jointly operated by all participating network groups.

The service was temporary. Docomo's recovery notice says its disruption ran from the afternoon of July 28 until 5:00 p.m. on July 30. As normal networks returned, full roaming was withdrawn and phones moved back to their contracted carrier.

This was not a one-off test. Since the April launch, the system had also been used after an Iwate forest fire and during Typhoon 6 disruptions in Okinawa and Kagoshima. The Kumamoto response showed that it could be activated again for a different disaster and ended when the damaged networks recovered.

How JAPAN Roaming works

Japan launched the nationwide service on April 1 through NTT Docomo, KDDI, Okinawa Cellular, SoftBank and Rakuten Mobile. The joint English announcement describes it as a way for a customer of a disrupted domestic carrier to use another participating carrier's 4G LTE network during a large disaster or major outage.

Operators decide whether to activate it, which area it covers and which of two modes applies. It does not appear during ordinary weak coverage or a minor local interruption.

The Telecommunication Carriers Association adds that toll-free, service and abbreviated numbers such as 0120, 0800, 0570, #7119 and #9110 do not work through the emergency network. Do not treat it as a complete replacement for the contracted mobile service.

What JPN-ROAM means on a phone

In full-roaming mode, a compatible phone should connect automatically and show JPN-ROAM or JpnRoam. The letter on a manually selected version identifies the rescue network:

• JPN-ROAM D for Docomo;
• JPN-ROAM K for KDDI or Okinawa Cellular;
• JPN-ROAM S for SoftBank;
• JPN-ROAM R for Rakuten Mobile.

Android users may need to enable data roaming for data to work. If the label appears but service does not, the official guidance says manual network selection may help. Select a listed JPN-ROAM network other than the unavailable contracted carrier.

Return network selection to automatic after the emergency service ends. Docomo and SoftBank both warn that leaving a phone locked to a manual rescue network can stop normal service from returning.

This setting advice is for a line that the provider says is eligible. Seeing a network name in a manual scan does not establish that a foreign SIM, travel eSIM or unsupported device can register on it.

Can a foreign visitor or travel eSIM use JAPAN Roaming?

The official eligibility language is domestic. It refers to customers of the participating Japanese mobile operators and to MVNOs that use those operators' infrastructure. Domestic MVNO customers can place emergency calls, and may use ordinary calls and SMS according to the activated mode and their contract; data works only for some MVNOs.

No source we reviewed says that an inbound international roaming profile receives the same access. A home carrier that normally roams on Docomo, KDDI, SoftBank or Rakuten may still lack the authorization, device profile or commercial arrangement required for JPN-ROAM.

The same limit applies to Roaming eSIM. The live Japan catalog includes plans whose network details name KDDI or au, NTT Docomo, Rakuten Mobile and SoftBank. That tells the traveler which terrestrial partners may carry ordinary package data. It does not confirm access to a separately activated emergency network.

Do not force a phone onto JPN-ROAM unless the line provider or emergency notice says it is eligible. A visible network is not a usable network, and leaving manual selection enabled can create a second outage after normal service returns.

Does every recent phone support the service?

No. Japan's carriers say voice-capable devices released from spring 2026 onward are scheduled to support both modes. Older phones need to appear on the contracted carrier's compatibility list, and some require current operating-system or carrier software.

The requirements are about more than LTE bands. Full roaming, emergency-call-only access and emergency alerts can have different device support. A phone may display JPN-ROAM but fail to complete a function.

eSIM support is another separate check. Passing the Roaming eSIM phone checker means the phone can install a digital profile. It does not certify JAPAN Roaming support. A physical SIM and an eSIM can both depend on the same carrier-device authorization.

What can 300kbps emergency data handle?

The full-roaming ceiling is 300kbps in both directions, before congestion and local signal conditions. Treat that as a limited information link, not normal travel broadband.

Short text messages, a lightweight web page, a simple map update or a low-bandwidth internet message may work. Streaming, cloud photo backups, app downloads, video calls and large ticket files are poor choices. A disaster can also load the surviving network far beyond normal demand.

Prepare the phone before an incident:

1. Save the hotel address and emergency contacts offline.
2. Download an offline map for each city or driving area.
3. Keep digital tickets and passport copies available without a connection.
4. Turn off automatic app updates, photo backup and video autoplay.
5. Use short text updates rather than repeated large uploads.
6. Follow evacuation instructions instead of moving around to find a faster signal.

An emergency network does not confirm whether a station, road, airport or attraction is safe. Use local authorities and transport operators for those decisions.

00000JAPAN is the visitor-accessible fallback

00000JAPAN is different from JAPAN Roaming. It is a public Wi-Fi network that participating hotspot operators can open during a major disaster or mobile outage.

KDDI's current guidance says any Wi-Fi-capable smartphone can use it, including devices from other carriers and MVNOs. No user ID or password is required. Open Wi-Fi settings and select the SSID 00000JAPAN when an official notice says it has been activated nearby.

There are two important limits:

• It only works near a participating public Wi-Fi hotspot; it is not nationwide mobile coverage.
• The connection is not encrypted. Avoid online banking, shopping, account changes and entering sensitive personal information.

During the Kumamoto response, SoftBank said 00000JAPAN was opened across Kumamoto Prefecture through available participating hotspots. That is a clearer fallback for an international visitor than assuming a foreign line can register on JPN-ROAM.

Safety Tips and emergency numbers for Japan visitors

Connectivity is only useful if the information is understandable. The Japan Tourism Agency's Safety Tips resources say the app provides push notifications and guidance for earthquakes, tsunamis, severe weather, volcanic eruptions, evacuation and heat in 15 languages.

Install the app and its language data before traveling. Also save the Japan Visitor Hotline: 050-3816-2787 in Japan or +81-50-3816-2787 from overseas. JNTO says it operates 24 hours a day, 365 days a year in English, Chinese, Korean and Japanese.

Japan's emergency numbers are:

• 110 for police;
• 119 for fire or ambulance;
• 118 for the Japan Coast Guard.

Do not make a test call. In emergency-call-only mode, the receiving service cannot call back through JAPAN Roaming, so give the location and essential details clearly before the call ends.

JAPAN Roaming or Roaming eSIM for a Japan trip?

The systems solve different problems. One is an operator-controlled rescue layer for an exceptional domestic outage. The other is a plan a visitor can choose for ordinary travel.

📶 JAPAN Roaming wins when Japan's operators activate a rescue network for an eligible domestic line. Roaming eSIM cannot create access to a network that has not authorized its profile.

🏆 Roaming eSIM wins for the trip a visitor can plan. The public Japan catalog returned 43 choices at 16:08 UTC on August 10. Across different plan details it listed KDDI or au, NTT Docomo, Rakuten Mobile and SoftBank, with speed labels up to 5G. Travelers can compare allowance, validity, activation and top-up fields before paying instead of waiting for a disaster mode.

Use the Japan Roaming eSIM page for a Japan-only trip. Compare the Asia Roaming eSIM when the itinerary crosses borders, or the Global Roaming eSIM for a wider route. Always confirm that the exact card includes every country and function you need.

Ten questions travelers ask about JAPAN Roaming

Is JAPAN Roaming active in Japan now?

Not as a permanent nationwide network. It is activated only for affected areas during a major incident. The Kumamoto full-roaming activation ended as normal service returned on July 30.

Will my foreign home-carrier line connect?

Do not assume it will. The published eligibility rules cover participating domestic operators and qualifying domestic MVNOs. They do not promise access to every inbound roaming line.

Will a Roaming eSIM connect to JPN-ROAM?

No current source confirms that. A plan may use a participating Japanese carrier for ordinary data without being authorized for the separate emergency service.

Which Japanese carriers participate?

NTT Docomo, KDDI, Okinawa Cellular, SoftBank and Rakuten Mobile launched the system. MVNO functions depend on the host network, service mode and contract.

Does any LTE or 5G phone work?

No. New voice-capable devices released from spring 2026 are scheduled for support, while older devices must be checked against the contracted carrier's list and kept updated.

What does JPN-ROAM on the screen mean?

It means the phone can see or has selected an emergency cross-carrier network. It does not by itself prove that every app, call or foreign line is authorized.

Should I select JPN-ROAM manually?

Only follow the provider's incident instructions for an eligible line. If manual selection is used, return the phone to automatic selection after the service ends.

Is 300kbps enough for maps and messaging?

It may support lightweight text, information and map use, but congestion and signal conditions matter. Save essential files offline and avoid video or large downloads.

Can emergency services call me back?

Not in emergency-call-only mode. It permits outgoing calls to 110, 119 and 118, but no callback. Full-roaming functions differ.

Can any visitor use 00000JAPAN?

Yes, when it is officially opened and a participating hotspot is nearby. It needs no carrier contract, ID or password, but it is unencrypted public Wi-Fi.

Sources and updates

The April 1 launch, participating operators, two service modes, 300kbps limit, emergency numbers, device guidance and network-selection steps come from the joint carrier announcement, TCA and current Docomo service page. The July 28 to 30 Kumamoto activation and recovery were checked against Docomo and SoftBank incident notices plus Japanese mobile-industry reporting. Earlier Iwate and Typhoon 6 activations were used only to establish that the system has operated in more than one incident.

KDDI and the Japan Tourism Agency were used for visitor-accessible emergency Wi-Fi and multilingual safety tools. They were not used to establish service eligibility.

The public Roaming eSIM Japan package endpoint was checked at 16:08 UTC on August 10. It returned 43 choices and listed KDDI or au, NTT Docomo, Rakuten Mobile and SoftBank across different plan network details. Current cards remain the source for availability and package terms.

Update policy: We will update this page for a new JAPAN Roaming activation, a foreign-roaming eligibility statement, changed mode or speed limits, additional carriers, material MVNO support, new device rules or a change to 00000JAPAN access.