Lots of the Blu-rays I own (bought in Europe) have audio and subtitle tracks in many languages. Often, they also contain Japanese. However, on most of those, the Japanese audio and subtitle track is on a separate title, as can be seen here for “Badlands”:
There is no other discernible difference between the titles. They are the same length, the video track is identical. I guess this means that whenever the Japanese title plays, customers will only be able to switch languages and subtitle between Japanese and English and not see any of the other languages.
Is there a technical, legal or cultural reason for this? If so, which one?