How to Activate an eSIM for Japan: Step-by-Step

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

How to activate an eSIM: step by step

Do this on stable Wi-Fi at home or your hotel — not at the airport where connections are slower and more congested.

iPhone (iOS 16+)

1. Settings → Mobile Data (or Cellular) → Add Data Plan.
2. Scan the QR code from your confirmation email, or paste the activation code manually.
3. Name the plan (e.g. "Travel eSIM") to distinguish it from your main SIM.
4. Set this line as your "Mobile Data" default.
5. Enable "Data Roaming" on that line: Settings → Mobile Data → your plan → Data Roaming.

Android (Pixel, Samsung, etc.)

1. Settings → Network & Internet → SIMs → Add eSIM (or "Download SIM").
2. Scan the QR code or enter the activation code.
3. Enable the new line and select it for "Mobile Data".
4. Settings → Network → your SIM → Roaming → enable Data Roaming.

Common mistakes

• "eSIM won't activate": check your phone is eSIM-compatible and carrier-unlocked.
• "I have eSIM but no internet": make sure that line is selected for data and Data Roaming is on.
• "My old SIM is still charging roaming": disable Mobile Data on your main SIM, or set it to calls/SMS only.

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.