We are getting a lot of questions about bad fonts, only '?' characters for non-latin languages, etc. We would clearly like to state to READ the readme bundled with the game, section '9. Troubleshooting', or online here.

To state this here shortly: you need to specify a font in openttd.cfg in the small_font/medium_font and large_font sections to get proper characters for Japanese, Russian, etc. Some languages have sprite-versions of the fonts available, you can put that in the [newgrf-static] section of the cfg file.

Completely unrelated, but Release Candidate 4 has a bug that it starts up in russian for the first time. The solution is to either try to find your way through all the '?'-s and change the language, delete russian.lng file or set 'language=english.lng' in the config file.