Chiming in to reinforce this point. I've had my locale set to JP for years now solely because of eroge, and it really doesn't make a difference for anything else that I run. It's much easier for me than having to resort to stuff like AppLocale, and it's basically guaranteed to work.
AppLocale in many cases was not up to the task of launching many eroge. The emulators that ran almost everything turned out to be “Locale emulator” and “NTleas”
"Locale emulator" allows you to configure the game to launch in other languages such as Korean, Taiwanese and others.
And "NTleas" was almost guaranteed to launch everything.
Although there were cases when it was necessary to change the language of the operating system, because nothing helped at all.
I have Japanese language support installed and can use the language itself to enter data from the keyboard. I don't remember any problems launching games from this developer.
Most often I saw complaints about a black screen at startup from other users on other forums or trackers. Most often, many problems were solved by excluding characters from other languages in the path to the game other than English, or by removing the read-only option from the game files.
