Oh!! I fixed it!! :)! You just need to change your system locale to japanese and restart!!
1. Go to settings and find your control panel
2. Click on “Clock and Regions”
3.Click on “Regions”
4. In “Regions” Click the administrative button (Should be on top)
5. Change system locale to Japan (you might be required to restart)
Oh I'm blind - I didn't see that you already tried that.. O_o
Sorry, I don't know what else could fix it (;′⌒`)