Japan eSIM: Prepaid 5G Data Plans

00000JAPAN is a free emergency Wi-Fi network that Japanese carriers, public Wi-Fi operators and local governments open after major disasters and, since September 2023, also during large-scale mobile outages. If your phone loses signal in an emergency, look for the network name 00000JAPAN: it is open and free to join. The connection is not encrypted, so use it to check news and contact family, and avoid entering passwords or card details.

Mostly, during the summer climbing season. Docomo lists 4G along the Yoshida, Subashiri, Gotemba and Fujinomiya trails year-round, and 5G and 4G on part of the summit and at mountain huts from early July to late August 2026. SoftBank also installs 5G and 4G equipment at the summit each season. Summit coverage reaches only part of the crater rim and can slow down when crowded, so save maps and hut bookings before you start.

Yes. GO, a taxi app that works in all 47 prefectures, accepts non-Japanese phone numbers and takes international credit cards and Apple Pay. Sign-up asks for your phone number and a verification code sent to it, and a data-only eSIM has no number, so register with your home SIM before you fly or keep it able to receive texts. GO no longer gives coupons to accounts verified with foreign numbers.

Yes. Install your eSIM before departure; once you land, simply enable data roaming to connect instantly at the airport.

Most iPhone XS and later, Samsung Galaxy S20 and later, and Google Pixel 3 and later support eSIM. You can check in your device’s Settings.

For most plans, validity starts from the first time your eSIM connects to a network at your destination. You can safely install it at home before flying. Exact details for each plan are clearly stated on its product page.

Most plans allow topping up data or extending validity: supported plans are clearly marked on the plan card and on the product page. You can also purchase a new plan anytime; the QR code is emailed to you within minutes.

eSIM plans for Japan connect via NTT Docomo, Rakuten Mobile, KDDI (au), SoftBank. Your device automatically selects the strongest local network; 5G is available where supported by the carrier, otherwise 4G/LTE applies. The specific carrier for each plan is listed on its detail page.

High-speed data is prioritized; after your daily allowance is used, speeds are reduced but remain sufficient for messaging, maps, and social media. You’ll never lose connectivity.

This data eSIM doesn’t include a phone number. You can still make calls and send messages normally using apps like WhatsApp, iMessage, Messenger.