Kindly be assured you can update your card information via the Sakura Mobile portal website.
Sakura Mobile Portal Website: https://myaccount.sakuramobile.jp/auth/login
If it's your first time to log-in the portal website, kindly refer to this article on How to log in to Sakura Mobile Portal for the first time?
1- After you log in your portal website, kindly click on the three dots on the upper right as shown in the below picture
2- From the menu, please select the option (Account):
3- From the Account page, you can see the current payment information, such as the cardholder name, payment method, the last 3 digits of the registered card, and the expiry date.
To change and update the registered card, kindly click on the pen mark as shown below:
4- From the next page, you can choose the option (Update Card Information).
5- Please fill in all the required information and submit the request.
We accept VISA, Master, JCB, AMEX, Discover, or Diners. We do NOT accept direct bank transfer, cash cards, or prepaid debit/credit cards.
If you face any issues when updating the new Credit/Debit Card, please contact us at email@example.com