This question in particular concerns using SoundHound/Shazam/MusixMatch or other commercial song identification apps in the United States to attempt to identify Japanese songs, but this question is conceivably relevant for the identification of non-Japanese songs as well.
A little context: the Japanese music industry is quite strict about keeping much of its music inside of its borders (at least digitally). For example, there are a lot of songs that have been released on the Japanese Amazon MP3 or iTunes stores, but they are nowhere to be found in the respective United States stores.
The Japanese music industry goes to great lengths to ensure that their music does not end up digitally outside of their country. For example, I have seen many Japanese songs get taken down Youtube very quickly after their uploads due to copyright violations.
Why can't commercial song identification apps identify certain songs, especially ones whose access is restricted to Japan? Shazam, etc. use audio fingerprinting to identify songs, so they must keep samples of the songs somewhere.
So my conjecture is that they can't identify Japanese songs because they can't legally keep samples due to Japan's policies concerning the digital distribution of their music.
Is this true? Or is there some other reason for why commercial song identification apps won't identify foreign songs?