Does Japanese user have the same privileges as the English one? Are both members of the same local groups?
What method (explicit user login, PI Trust or Windows Integrated Security) is used for authentication with the PI Server?
Can you try using AboutPI-SDK.exe or PISDKUtility.exe to connect to PI using the Japanese user?
Can you check if the complete stack trace is in the Application Event Log?
Issues like the one your are reporting are difficult to troubleshoot via the forum. It might be more effective to open a ticket at OSIsoft Technical Support and to ask for a remote session.
Thanks Gregor. I submited a help request to the support team