ありがとうございます。
Can I change my account's username?accounts@ppy.sh に英語でメールをしてコンタクトを取ってください。削除もしくは名前変更の対応をしてもらえる可能性はあります。
Yes, absolutely!
If you have purchased (or been gifted) a supporter tag at any point, you will be a able to change your name once for free. This name change can be redeemed at the osu!store.
At any point thereafter, you may purchase a username change to change your name to whatever you wish. However, each change will become progressively more expensive - the second will cost $8 USD, the third $16 USD, and so on. We do this to prevent people from abusing the system to change their names in rapid succession.
If you are only after minor capitalization or grammar/spelling changes, you can email accounts@ppy.sh to request a free name change to fix these issues. We will not charge you for these sorts of name changes, but you MUST do them through a support email.