Language option

Hello everyone.

I play on Windows 10, Steam’s version with Japanese as system language. I wanted to change it to English but… there is no possibility for it. I tried change my system language, looking for config files, delete game, clean registr and local files, turn off Steam “Cloud Sync”, and instal game one more time. It doesn’t help.
I tried to instal a game from Internet. Probably, old version, but this one has a language change option in game’s menu.
So, there is the question: if You, developers, removed the language change-option from game, how am I supposed to change language now?

P.S. There are some .sav-files. I cannot work with .sav-files, but I don’t think, that I should, for just change a language.

Thank You for Your time.