The SIM unlocking can be done at the My au website. Please refer to the steps below.
Select the au phone number you want to proceed, and tap on "Selection" [選択].
Enter the 4-digit PIN number set at the contract, and tap on "Next" [次へ].
Tap on "For purchases with au / UQ mobile" [au/UQ mobile で購入した端末].
The terminals whose purchase history can be confirmed will be displayed in a list.
Put a check on the terminal you want to unlock SIM and tap "Next"[次へ].
Select "Reason of cancellation" [解除の理由] and "Contact" [連絡先] from the pull-down, tap on "Apply with this content"[この内容で申し込む].
A temporary registration completion screen will be displayed and an e-mail will be sent to the contact e-mail address.
Tap on the URL in the e-mail received.
The procedure to unlock SIM is completed.
Has your problem been solved?