Before choosing a SoftBank or Y!mobile eSIM in Japan

An eSIM removes the plastic card, but it does not remove identity checks, contract eligibility or phone compatibility checks. Start with your length of stay and your exact phone model.

Quick answer

If you will live in Japan, prepare your current Japanese address, accepted identity documents, payment method and the exact model number of your phone. If you are only visiting, compare travel eSIM, prepaid SIM and roaming instead of assuming a regular monthly plan will fit.

First, choose the route that matches your stay

You are moving to Japan

A regular voice-and-data plan may suit you. The carrier decides whether your documents, residence status, payment method and application meet its current requirements.

You are visiting temporarily

A monthly contract may not be the right route. Compare validity, data amount, voice and SMS support, activation timing, hotspot rules and help available in your language.

You want to keep a Japanese number

Check the current account holder and the official MNP process before applying. Do not cancel the old line first unless your current provider specifically instructs you to do so.

Six checks before opening an application

Identity and address: confirm which original identity and supplementary documents are accepted, and make sure your current address matches.
Payment: prepare a payment method accepted by the carrier. The applicant, user and payer may require additional confirmation when they are different people.
Exact phone model: check the model number, where it was purchased, SIM-lock status, supported bands and the carrier's compatibility list.
eSIM support: confirm that your phone supports eSIM and is not restricted by another carrier. A phone being “eSIM capable” does not guarantee service compatibility.
Wi-Fi and account access: have stable Wi-Fi, your device passcode and access to the account used by your phone. Keep the old phone powered and nearby during transfer.
Final activation: after setup, test calls, mobile data and SMS before erasing the old phone or deleting its eSIM.

Online application screens may be primarily in Japanese. Never send identity documents, payment details, passwords or an eSIM QR code to an unofficial helper. Enter them only on the carrier's official page.

Which brand should you check?

Check Y!mobile if…

You want to compare a smaller set of plans and will verify family, home-internet and payment discounts separately. Confirm the latest plan, fee and eSIM conditions on the official application page.

Check SoftBank if…

You want to compare SoftBank plans, devices or support options. Separate the monthly service fee, device price, discounts and any return programme before deciding.

Pause if…

Your model number, accepted documents, address or payment details are unclear. Resolve these points before submitting; approval and installment eligibility are never guaranteed.

Check the current official application conditions

Choose only the brand you intend to review. Confirm prices, discounts, eligibility, device compatibility and the complete order summary on the destination page.

Official application links (advertising)

Check Y!mobile application conditions →Check SoftBank application conditions →

Official sources checked

Information checked on September 13, 2026. Requirements and supported devices can change, so re-check the official pages immediately before applying.