eSIM / Wi-Fi / Phone Setup
Data plan, setup window, what to do when signal drops.
eSIM before takeoff. Activate on landing. Free Wi-Fi is backup, not plan.
Which eSIM
For most trips: Airalo or Ubigi. Wide carrier coverage, reasonable pricing, app-based setup. Both work on landing without a store visit.
For rural and mountain coverage: pick a Docomo-network plan. Tokyo, Osaka, Kyoto — every plan works. Hakone, Hokkaido backcountry, Yakushima — Docomo coverage is the safer default.
For longer stays or local-SIM features (Japanese phone number, native carrier billing): Sakura Mobile or Mobal handle the foreigner-friendly side of this.
Set up before you fly
Buy the plan and download the eSIM profile while you’re still on home Wi-Fi. The QR code or installation link doesn’t activate until you toggle the line on — but the install itself often needs network signal to complete.
Most providers let you set the activation date to your landing day. Triple-check that date before you leave.
Activate on landing
Land. Connect to airport Wi-Fi. Toggle the new line on. Disable your home line’s data roaming.
If the new line shows “no service,” restart the phone once. Most “my eSIM doesn’t work” issues resolve there.
Free Wi-Fi as backup
JR-EAST_FREE_Wi-Fi works in most major JR East stations, including the full Yamanote Line and Travel Service Centers. Metro_Free_Wi-Fi covers select Tokyo Metro stations (email signup, 3-hour sessions).
Free Wi-Fi is fine for messaging from a station while you sort out a dropped eSIM. Don’t rely on it for navigation between stations, or for anything time-sensitive on a moving train.
If you need a physical SIM
Bic Camera and Yodobashi sell short-term tourist SIMs at airport branches and major-city stores. Setup is more steps than an eSIM — passport verification, manual APN — but works on any unlocked phone that supports Japan’s bands.
Skip airport kiosks selling unbranded tourist SIMs. Pricing is high and coverage is inconsistent.