Go inside the game folder, search through all of the folders and try to find an .ini (text) file (eg. - "steam_emu.ini", "settings.ini" or ... etc. The file might also be called "settings.txt"). If it exists, open the file with Notepad, search for the language setting (eg. - language = japanese), edit the setting so that it is one of the game's supported languages which you want to use, save the changes and then try to run the game again.