Correcting you...
The product exists on any PC in any country.
What likely doesn't exist is a Japenese user interface. So, if you can't read English, you won't know how to operate the software.
Now, converting to Japenese is a bit more difficult than converting to Spanish; but, its the same principle. You take all the text in your applications menus, buttons, screens, etc. and place them in a generic black box. Then, depending on what language the user has configured on their PC, you plug in the Japanese language black box, the Spanish language black box, etc. Voila!, when the application starts, you get your specific flavor of ETS.
You don't have to be a brain surgeon to do the translation, but it can be very tedious work though and take time.