Short answer
Apple says to connect an iPhone to a Wi-Fi network or hotspot before adding an eSIM, and in some countries and regions an eSIM-only iPhone can set one up without Wi-Fi. Samsung says to connect a Galaxy to Wi-Fi or a mobile data network before adding a plan.
Airport Wi-Fi names are on the Japan eSIM settings on arrival page. When to install, and when the plan starts counting, are already covered in When should I install my Japan eSIM, and when does the plan start?.
Fact table
As of 2026-10-21
Each claim names its source. The full source list, with the date each page was read, is below.
| Claim | Source |
|---|---|
| Apple says to connect the iPhone to a Wi-Fi network or hotspot to set up an eSIM, and that in some countries and regions an eSIM-only iPhone can activate without a Wi-Fi network. | Apple Support, set up eSIM |
| Apple says you can open the Camera app and scan a QR code. On iOS 17.4 or later, Apple says you can tap and hold a QR code in the default email app or a browser and then tap Add eSIM. Apple also says you can enter the details manually under Settings, Cellular or Mobile Data, Add Cellular Plan, Enter Details Manually. | Apple Support, set up eSIM |
| Samsung says to connect the Galaxy to Wi-Fi or a mobile data network before adding a plan. | Samsung, add a Galaxy eSIM |
| Samsung's Galaxy eSIM article updated 16 September 2026 says the QR path is Settings, Connections, SIM manager, Add eSIM, then Scan QR code, and that the eSIM is then downloaded and activated on the phone. The manual path on that page is Add eSIM, then Scan QR code, then Enter activation code. | Samsung, Galaxy eSIM QR setup |
| The Japan eSIM guide is the write-up for when to install. This page does not set another time. | Wakamo Japan eSIM guide |
| The Japan plan page shows when the plan you are viewing starts counting. This page states no day count. | Wakamo Japan plan page |
FAQ
Can I add the Japan eSIM before the flight, or only after I land?
Apple says to connect the iPhone to a Wi-Fi network or hotspot to set up an eSIM, and that in some countries and regions an eSIM-only iPhone can activate without a Wi-Fi network. Samsung says to connect the Galaxy to Wi-Fi or a mobile data network before adding a plan. The Japan eSIM guide is the write-up for when to install. This page does not set another time.
Does adding the eSIM require Japanese cellular service?
Apple says to connect the iPhone to a Wi-Fi network or hotspot to set up an eSIM, and that in some countries and regions an eSIM-only iPhone can activate without a Wi-Fi network. Samsung says to connect the Galaxy to Wi-Fi or a mobile data network before adding a plan. This page does not claim the download needs a Japanese network.
Can I scan the QR code with the same phone?
Apple says you can open the Camera app and scan a QR code. On iOS 17.4 or later, Apple says you can tap and hold a QR code in the default email app or a browser and then tap Add eSIM. Apple also says you can enter the details manually under Settings, Cellular or Mobile Data, Add Cellular Plan, Enter Details Manually. Samsung's Galaxy eSIM article updated 16 September 2026 says the QR path is Settings, Connections, SIM manager, Add eSIM, then Scan QR code. The manual path on that page is Add eSIM, then Scan QR code, then Enter activation code. This page does not claim a Galaxy can scan a code displayed on its own screen.
Does the phone need Wi-Fi?
Apple says to connect the iPhone to a Wi-Fi network or hotspot to set up an eSIM, and that in some countries and regions an eSIM-only iPhone can activate without a Wi-Fi network. Samsung says to connect the Galaxy to Wi-Fi or a mobile data network before adding a plan.
Can I add the eSIM on the airplane?
Apple says to connect the iPhone to a Wi-Fi network or hotspot to set up an eSIM, and that in some countries and regions an eSIM-only iPhone can activate without a Wi-Fi network. Samsung says to connect the Galaxy to Wi-Fi or a mobile data network before adding a plan. This page does not claim that an airplane network completes the download.
When does the plan's validity start?
The Japan plan page shows when the plan you are viewing starts counting. This page states no day count. The Japan eSIM guide is the write-up for when to install. This page does not set another time.
Sources
Apple Support, set up eSIMsupport.apple.com
Connect the iPhone to a Wi-Fi network or hotspot. In some countries and regions, eSIM-only iPhone models can activate without a Wi-Fi network. After setup, the Camera app can scan a QR code. On iOS 17.4 or later, tap and hold a QR code in the default email app or a browser, then tap Add eSIM. Manual entry is Settings, Cellular or Mobile Data, Add Cellular Plan, Enter Details Manually.
Accessed 2026-10-21.
Samsung, add a Galaxy eSIMsamsung.com
Updated 22 January 2025. Before adding a plan, connect the Galaxy to Wi-Fi or a mobile data network. This answer cites that connection sentence only.
Accessed 2026-10-21.
Samsung, Galaxy eSIM QR setupsamsung.com
Updated 16 September 2026. QR path: Settings, Connections, SIM manager, Add eSIM, Scan QR code. The eSIM is then downloaded and activated on the phone. Manual path: Add eSIM, Scan QR code, Enter activation code. On this page, Wi-Fi is required together with Bluetooth when transferring an eSIM from an iPhone, not on the QR steps.
Accessed 2026-10-21.
Wakamo Japan eSIM guidewakamo.io
Wakamo product information. The Japan eSIM guide is the write-up for when to install. This answer links that guide and does not set another time.
Accessed 2026-10-21.
Wakamo Japan plan pagewakamo.io
Wakamo product information. The plan page shows when the plan you are viewing starts counting. This answer states no day count.
Accessed 2026-10-21.