Roamclarity

What breaks when you travel on a data-only eSIM — checked country by country.

Japan · The default messaging app in Japan — restaurants, hotels and shops use it

Can you use LINE in Japan without a Japanese phone number?

Requirements vary — review the source

LINE sign-up depends on your country of residence. Phone verification is used in Hong Kong, Japan, Korea, Taiwan and Thailand; other countries use Apple or Google. Check the official route for your residence.

Check everything you plan to do in Japan →

Source recheck / 29 October 2026

LINE sign-up depends on your country of residence. Phone verification is used in Hong Kong, Japan, Korea, Taiwan and Thailand; other countries use Apple or Google. Check the official route for your residence.

Open official source ↗

ROAMCLARITY / FIELDNOTES

Take your fieldnotes with you.

Create a key-based account to save this Japan plan across devices. No email or phone number required.

Sign in with account key

Privacy & account information

Device saves stay in this browser. Account saves store selected activities and the home-SIM setting in our Cloudflare database until you delete the account. Sessions expire after seven days. Your random account key is stored only as a hash on the server; keep your copy safe. We do not collect an email, name or phone number. Optional analytics store daily event totals by channel and language, without linking them to an account. Short-lived network digests are used for abuse control and are used in ten-minute windows, with expired records cleaned up on subsequent limited requests. Cloudflare may process request metadata to operate and secure the service. Contact [email protected] for questions. This service provides preparation guidance, not a guarantee that an app will accept you. Calculator amounts and inputs are processed in the browser and are not included in optional event counts.

Your choices, clearly explained.

Device saves stay in this browser. Account saves store selected activities and the home-SIM setting in our Cloudflare database until you delete the account. Sessions expire after seven days. Your random account key is stored only as a hash on the server; keep your copy safe. We do not collect an email, name or phone number. Optional analytics store daily event totals by channel and language, without linking them to an account. Short-lived network digests are used for abuse control and are used in ten-minute windows, with expired records cleaned up on subsequent limited requests. Cloudflare may process request metadata to operate and secure the service. Contact [email protected] for questions. This service provides preparation guidance, not a guarantee that an app will accept you. Calculator amounts and inputs are processed in the browser and are not included in optional event counts.