Preparing Your Japan Connection: Complete Checklist Before Departure
TL;DR
Preparing your internet connection before traveling to Japan takes 4 steps spread over one week: check your phone's compatibility and order an eSIM (D-7), install the eSIM profile and download your offline apps (D-3), configure dual SIM and disable roaming (D-1), then activate your mobile data upon landing (Day D). Follow this checklist and you'll be connected on the NTT Docomo network within 30 seconds at Narita or Haneda.
Why you should prepare your connection before departure
In Japan, free WiFi is much less common than you might think. Public networks in train stations, konbini, or cafes do exist, but they're often slow, time-limited (30 minutes max), or require registration with a Japanese phone number. Outside Tokyo and Osaka, hotspots become even rarer.
The result: if you haven't prepared your connection before takeoff, you risk finding yourself without internet at the airport — exactly when you need it most (finding your train, activating your Suica, contacting your accommodation).
The good news is that with an eSIM and 15 minutes of preparation spread over the week before departure, everything is sorted before you even board the plane.
D-7: Check compatibility and order your eSIM
One week before departure, you have time to check everything calmly. This is the most important step — and the one that prevents 90% of airport headaches.
Check that your phone supports eSIM
All recent smartphones are compatible, but it's better to make sure now rather than at the boarding gate. The check takes 30 seconds:
On iPhone (XS and newer, including iPhone 17):
- Go to Settings > General > About
- Look for the "EID" line
- If an EID number appears, your iPhone supports eSIM
On Android (Samsung Galaxy S21+, Google Pixel 3a+, Xiaomi, etc.):
- Go to Settings > About Phone > SIM Status
- Look for an EID number
- If it's there, you're good to go
For a detailed guide by model, check out our eSIM iPhone compatibility article.
Important note: your phone must be unlocked (carrier-free). If you bought it with a carrier plan, verify that it's unlocked — most are automatically unlocked after 3 months, but a quick call to your carrier will clear any doubt.
Choose your eSIM plan
Your choice depends on the length of your stay and your habits:
| Profile | Length of stay | Recommended plan |
|---|---|---|
| Minimalist (Maps, transit, searches) | ≤ 1 week | 10 GB |
| Standard (social media, photos, Maps) | 10-12 days | 20 GB |
| Intensive (video, FaceTime, hotspot) | 2+ weeks | 50 GB (recommended) |
| Unlimited (streaming, remote work) | Any length | Unlimited |
Our advice: the 50 GB plan is the safest choice for most travelers. Google Maps in navigation mode uses about 50 MB/hour, add Instagram, translations, and a few video calls, and you'll easily reach 1.5 to 2 GB per day.
Order your eSIM
Ordering takes 2 minutes. You receive your QR code by email immediately after purchase — no waiting for delivery, no package to pick up. That's one of the big advantages of eSIM over a physical SIM card.
At PlanJapan, all eSIMs run on the NTT Docomo network — the most reliable in Japan, with 99.9% coverage, including rural areas, the Shinkansen, and the islands.
D-3: Install the eSIM and prepare your offline apps
Three days before departure, you're still comfortably at home, on WiFi. This is the ideal time to install your eSIM and prepare everything that will work offline.
Install the eSIM profile (without activating it)
Installation and activation are two different things. Installing the eSIM profile doesn't start your plan — it simply prepares your phone to connect to the Japanese network when you decide to.
On iPhone:
- Go to Settings > Cellular > Add eSIM
- Scan the QR code received by email
- Name the plan (for example "Japan" or "PlanJapan")
- When asked if you want to activate this line, choose "Later" or disable it for now
On Android:
- Go to Settings > Network & Internet > SIM cards > Add eSIM
- Scan the QR code
- Download the profile and don't activate it yet
For detailed steps on iPhone, our eSIM activation guide for iPhone walks you through it screenshot by screenshot.
Why not activate now? Some eSIM plans start their day counter upon activation. By installing without activating, you keep your full plan duration for your time in Japan. To learn more about optimal timing, check our article on when to activate your Japan eSIM.
Download Google Maps in offline mode
Google Maps is essential in Japan — the transit network is complex, and Japanese addresses don't follow the same logic as Western ones. Download offline maps for the areas you'll visit:
- Open Google Maps
- Search for the city or area (e.g., "Tokyo," "Kyoto," "Osaka")
- Tap your profile picture > Offline maps
- Select the area and download
Each area weighs between 100 and 400 MB. In case of temporary connection loss (tunnel, deep subway), you'll still have access to the map and navigation.
Download the Japanese pack on Google Translate
Japanese uses three writing systems (hiragana, katakana, kanji), and very few signs are translated outside major stations. Download the Japanese pack for offline translation:
- Open Google Translate
- Tap the source or target language
- Search for Japanese and tap the download arrow
- The pack includes camera translation — very useful for restaurant menus
Other apps to prepare
- Suica / Pasmo (in Apple Wallet or Google Wallet) — rechargeable transit card for subway, bus, and local trains
- Japan Travel by Navitime — train schedules in English, multimodal itineraries
- Tabelog or Google Maps reviews — to find restaurants (Tabelog is Japan's TripAdvisor, much more reliable for local cuisine)
D-1: Final checks and dual SIM configuration
The day before departure, everything is installed. All that's left is to verify everything works and prepare the switch between your home SIM and your Japanese eSIM.
Verify that the eSIM is properly installed
A quick check to avoid surprises:
On iPhone:
- Go to Settings > Cellular
- You should see two lines: your home plan and the PlanJapan plan
- The PlanJapan plan should show "Inactive" or "No Service" status — that's normal, it will activate in Japan
On Android:
- Go to Settings > Network & Internet > SIM cards
- Verify that the PlanJapan eSIM appears in the list
Configure dual SIM
Your phone can manage two lines simultaneously: your home SIM (for calls and texts) and your PlanJapan eSIM (for mobile data in Japan). Here's how to set up the coexistence:
On iPhone:
- Go to Settings > Cellular
- Tap Cellular Data (the configuration line, not the toggle)
- Select your PlanJapan plan as the default data line
- Keep your home SIM as the default voice line
On Android:
- Go to Settings > Network & Internet > SIM cards
- Set the PlanJapan eSIM for mobile data
- Keep your home SIM for calls
Disable data roaming on your home SIM
This is the step many people forget — and it can be expensive. Even with an active Japanese eSIM, if roaming is enabled on your home SIM, your phone may switch to it automatically and generate charges.
On iPhone:
- Go to Settings > Cellular
- Tap your home plan
- Turn off Data Roaming
On Android:
- Go to Settings > Network & Internet > SIM cards
- Select your home SIM
- Turn off Data Roaming
Tip: you can also enable airplane mode on your home SIM and only keep the PlanJapan eSIM active. This also saves some battery.
Day D: Activation at the airport in 30 seconds
You're on the plane, the landing announcement just came through. Here's exactly what to do:
Step 1: Turn off airplane mode
As soon as the "fasten seatbelts" sign turns off (or when the wheels touch the tarmac, depending on your patience), turn off airplane mode.
Step 2: Enable cellular data on the PlanJapan eSIM
On iPhone:
- Go to Settings > Cellular
- Verify that the PlanJapan line is selected for cellular data
- Turn on the Cellular Data toggle if it's not already on
On Android:
- Go to Settings > Network & Internet > SIM cards
- Enable the PlanJapan eSIM for mobile data
Step 3: Verify the connection
Within a few seconds, you should see "NTT DOCOMO" or "docomo" appear in the status bar. Open a browser or an app — if the page loads, you're connected.
If the connection doesn't establish immediately, don't panic. The network may take 1 to 2 minutes to connect, especially in airport areas where the signal bounces around. Try toggling airplane mode on and off once — this forces a network search.
And there you go: you have internet in Japan before you even pick up your luggage. You can check the route to your hotel, buy your Narita Express or Limousine Bus ticket, and let your family know you've arrived.
Summary checklist: Check everything before you leave
Here's the complete checklist to follow step by step. If all items are checked, you're ready:
D-7 — Preparation
- ☐ Check your phone's eSIM compatibility (EID number present)
- ☐ Verify your phone is unlocked (carrier-free)
- ☐ Choose your eSIM plan (10, 20, 50 GB or unlimited)
- ☐ Order your eSIM from PlanJapan
- ☐ Keep the email with the QR code (don't delete it!)
D-3 — Installation
- ☐ Scan the QR code and install the eSIM profile
- ☐ Do NOT activate the eSIM yet
- ☐ Download Google Maps offline maps (Tokyo, Kyoto, Osaka, etc.)
- ☐ Download the Japanese pack on Google Translate
- ☐ Set up Suica/Pasmo in Apple Wallet or Google Wallet
- ☐ Install Japan Travel by Navitime (optional but recommended)
D-1 — Configuration
- ☐ Verify that the eSIM appears in SIM settings
- ☐ Configure dual SIM: PlanJapan eSIM = data, home SIM = calls
- ☐ Disable data roaming on your home SIM
- ☐ Charge your phone to 100%
- ☐ Bring a charger/power bank (days in Japan are long)
Day D — Activation
- ☐ Upon landing, turn off airplane mode
- ☐ Verify cellular data goes through the PlanJapan eSIM
- ☐ Wait for "NTT DOCOMO" to appear in the status bar
- ☐ Open a web page to confirm the connection
- ☐ Enjoy Japan, connected
5 mistakes to avoid
Even with this checklist, some mistakes keep coming up. Here are the most common pitfalls:
1. Waiting until the airport to do everything
This is the number one mistake. Installing an eSIM requires a QR code, a stable WiFi connection, and 5 minutes of calm. At Narita or Haneda, after a 12-hour flight, with jet lag and fatigue, it's not the time to configure anything. Do it at home, on WiFi, with a clear head.
2. Forgetting to disable roaming on your home SIM
If your home SIM has roaming enabled, your phone may use it for data instead — even if the Japanese eSIM is installed. Result: roaming charges of several dollars per megabyte, and an unpleasant surprise on your next bill.
3. Deleting the email with the QR code
The eSIM QR code can only be scanned once. If you switch phones, do a factory reset, or accidentally delete the eSIM profile, you'll need the original QR code or customer support. Keep the email in a dedicated folder, and save a screenshot to the cloud.
4. Confusing "install" with "activate"
Installing the eSIM profile and activating data are two separate steps. Installation prepares your phone. Activation starts the plan (and the day counter, depending on the provider). If you activate too early, you lose plan days. The rule: install at D-3, activate on Day D.
5. Not downloading offline apps and maps
Even with an eSIM, there are times when the connection may be weak: Tokyo subway tunnels (Oedo line in particular), very rural areas of Hokkaido, inside certain concrete buildings. Offline maps and the translation pack are your safety net.
Frequently asked questions
How long does it take to prepare your connection before a trip to Japan?
In total, count 15 to 20 minutes spread over the week before departure: 5 minutes to check compatibility and order (D-7), 5 to 10 minutes to install the eSIM and download offline apps (D-3), 3 minutes to configure dual SIM (D-1), and 30 seconds to activate upon landing (Day D).
Can you install a Japan eSIM without WiFi?
Technically, you can scan the QR code with a mobile data connection. But we strongly recommend doing it on WiFi, at home, to avoid connection issues during installation. Downloading the eSIM profile requires a stable connection.
When exactly does my eSIM plan start?
At PlanJapan, the day counter starts at the first connection to the Japanese network — not at purchase or installation. You can buy and install your eSIM a week before departure without losing a single plan day. For details, check our article on when to activate your Japan eSIM.
Do I need to remove my home SIM before using the eSIM?
No. Dual SIM lets you keep your home SIM active (to receive calls and texts) while using the PlanJapan eSIM for mobile data. You don't need to physically remove anything.
What if the eSIM doesn't connect at the airport?
First, don't panic — it's rare but it happens. Try these three things in order: (1) toggle airplane mode on and off to force a network search, (2) verify that cellular data is set to the PlanJapan eSIM line, (3) restart your phone. If the problem persists, contact PlanJapan support — we respond even from the airport.
Does this checklist also work for arriving at Osaka-Kansai (KIX)?
Yes, exactly the same way. The PlanJapan eSIM works across all of Japan via the NTT Docomo network. Whether you land at Narita, Haneda, Kansai (Osaka), Chubu (Nagoya), Fukuoka, or New Chitose (Sapporo), the process is identical: turn off airplane mode upon landing and the network connects within seconds.
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Our recommendation
Preparing your internet connection before traveling to Japan isn't complicated — you just need to start early enough. With this 4-step checklist (D-7, D-3, D-1, Day D), you eliminate 100% of connectivity stress.
For most travelers, the 50 GB PlanJapan plan on the NTT Docomo network offers the best balance: enough data for 2 to 3 weeks of intensive use, hotspot included with no restrictions, and support if needed.
If you're traveling with family, working remotely, or simply don't want to count your gigabytes, the unlimited plan is the zero-stress choice.