If you have a question about something regarding UTAU you're
far more likely to get help with it if you title your thread with a short description of the issue. To me, and surely to others, this title didn't look like a serious one. Help questions also don't go in the
Support and Feedback area of the forum; that section is for actual UtaForum
site based issues, like the forum loading improperly. If you have a question in the future, you should post it in
UtaHelp.
Anyway. You've told us nothing about your operating system. I'm going to assume it's Windows 10.
Are you absolutely certain you changed your locale properly? You should be able to write more than あ if so.
If you type 'locale' into the start menu, you'll get this screen.
Off to the right-hand side, go to 'Additional date, time, & regional settings'.
Hit 'Region'. Go to the administrative tab.
Hit 'change system locale'. Make it Japanese (Japan). Restart computer.