Crossing Borders Overland from Japan: Internet & eSIM

eSIM from 1,00 USD · 100 MB. Networks: KDDI/au (5G), NTT docomo (4G), NTT docomo (5G), Rakuten Mobile (5G), SoftBank (5G).

Internet when travelling overland and crossing borders from/to Japan

What happens to your eSIM at the border

• Single-country plan: you lose coverage when you cross the border. You'll need a new plan for the next country.
• Regional plan (Europe / Americas / Asia etc.): it keeps working — your eSIM automatically connects to the local network in the new country. But confirm the destination country is included in the plan's coverage.
• Advantage of eSIM over physical SIM: you can have multiple eSIM profiles installed (one per country) and switch between them without opening the phone.

At the border itself

• Near the border your phone may jump between networks from both countries. This can trigger unexpected charges if roaming is active on your main SIM.
• Turn off data on your main SIM and use the travel eSIM only to avoid surprises.
• GPS works without data (for offline maps), so you won't get lost even if you lose signal briefly.

Tips for long overland routes

On some highways between cities (Deep mountain areas (Nikko and Hakone lake districts)), you may lose signal for stretches. Download offline maps for the entire route and save offline the addresses of stops, accommodation and emergency contacts before you set off.

Quick checklist: stay online without surprises

The make-or-break moment is often the first 30 minutes after landing: maps, transport, messages. Install your eSIM on Wi‑Fi before you travel and switch mobile data to the eSIM when you arrive. That way you're not dependent on airport Wi‑Fi and you avoid accidental roaming charges.

For typical use (maps + messaging + light social media), 1–3 GB per week is often enough. If you tether for a laptop, take video calls, or stream daily, aim for 10 GB+ or a plan with fair-use throttling instead of a hard cut-off.

• Networks: KDDI/au (5G), NTT docomo (4G), NTT docomo (5G), Rakuten Mobile (5G), SoftBank (5G)
• Offline maps: download the area in Google Maps, Apple Maps, Yahoo! Japan Maps while you're on hotel Wi‑Fi.
• On the move: GO (taxi), S.RIDE, DiDi Japan + LINE, WhatsApp work well on low data — video and app updates are usually the real data drains.
• Common weak spots: Deep mountain areas (Nikko and Hakone lake districts) · Remote islands (Yakushima, Iriomote in Okinawa)
• City context: Tokyo: Excellent coverage; Metro LTE on most lines; dense buildings can blip indoors. · Osaka: Strong 4G/5G; Dotonbori and Namba districts well-covered.

Phone setup tip: keep your primary SIM active for calls/SMS (so 2FA codes can arrive), but turn off mobile data on that line. Set the eSIM as your data line — it prevents accidental roaming on the wrong SIM and keeps WhatsApp/banking flows more predictable.

Current eSIM plans (examples)

Examples from our database — availability and pricing can change.