For the vinyl era? There's no such thing, I think. I'm no expert on Japanese music, TV or film, but I think they stocked a lot of foreign libraries. Especially British, German and Italian seem prevalent from what I've seen.
There are probably more, but the only contemporary Japanese label I know of is Groovers Music Library, which was founded 1991.
There are
tons of soundtracks, however, and I know there are a few record shops in Japan that stock large amounts of library LPs! Check out
Dessinee, for instance.
- Safe travels and happy digging