I accidentally wrote the region as the region of China, how to ensure that I revert to the Japanese

The country associated with your adobe id must match the store you purchase from and must match the payment address. otherwise, change what's necessary:

change your country on adobe.com, https://www.adobe.com/international/selector/

change country associated with adobe id - https://helpx.adobe.com/x-productkb/policy-pricing/change-country-associated-with-adobe-id.html

change credit card and/or billing address, https://helpx.adobe.com/manage-account/using/update-billing-information.html

change currency - https://forums.adobe.com/thread/1999694

change store - http://www.adobe.com/store_selector/storeselector.html

change adobe.com website language - https://forums.adobe.com/thread/1999693

change age - https://helpx.adobe.com/nz/creative-cloud/kb/you-eligible-cc.html