After seeing some of the messages here, I did some tests and Japanese Locale is not the issue here. Don't ask me why, but I do use Japanese Locale as default on my PC and I still triggered the many bugs. However, the bugs did disapear when I changed my Date/Time format to Japanese (was still using my local ones).
So, as far as I checked, you just need to change your Regional format to Japanese without changing your System Locale or your Region or your System Language.
Still a pain, but it is reassuring :
1) You have a workaround to play the game
2) Though unusual, there are games with this problem from time to time, so it's a known issue. Not common, but not rare either.
3) It's not a botched release from the Dev : the game work fine, it just has some quirks on foreign systems. Can't really blame the guy for missing that. Why would you expect a change in your Date format to screw your interface up ?
Let's just hope he manage to cook a fix up. We'll see.
EDIT : Oh, and in case someone doesn't know how...
Settings -> Time & Language -> Region -> Additional date, time & regional settings -> Region -> Formats -> Change the format to Japanese