Hi ​@YAMAICHI DOKEN! Welcome to the Box Community! We're sorry to hear that you wish to stop using Box services. However, I'd be happy to assist you.

Canceling your Box account depends on your plan type (e.g., individual or business). Please refer to this article for step-by-step instructions: Canceling Your Box Account.
 

Once the cancellation is processed, the account owner or administrator will receive a confirmation email. If no confirmation is received or the administrator is unable to cancel the account, please contact our Cancellations Team at cancel@box.com for assistance.

We appreciate your business and hope you'll consider using Box again in the future! 💙