Hi, ​@takashi yoshihara! Welcome to the Box Community! As we can only provide assistance in English, I have translated the content to help better understand the issue.

If your account was originally set up using Google Sign-In, you can reset your password by visiting this link: https://app.box.com/reset. This will allow you to create or reset forgotten password and log in to Box using your username (the email you registered with) and password.

Please let us know if this resolves the issue with logging in. If not, we will escalate the matter to our Product Support team for further assistance.

I look forward to hearing from you. 

Thanks for the reply.
The problem could not be resolved.
After resetting my password, I tried to log in, but the same dialog came up and I could not log in.

Hello ​@takashi yoshihara, sorry to hear you’re still unable to login. Have you already tried clearing your cache/cookies then resetting via https://app.box.com/reset?

Please let me know if you’re able to login. Otherwise, I’ll submit a ticket for further assistance.

Thanks, and have a great day!