I think Dimarzio were the OEM for those pickups. I had the same pickups in a Westone Thunder bass. In theory they are just Model P pickups, though I found that mine were unpotted and pretty microphonic.
Dimarzio made pickups for the Japanese builders for a while; things like a Super Distortion without the 4-wire hookup (technically more like a Super 2, but with slugs instead of hex poles), which show up in Hondo guitars.
Japan being Japan, I wouldn't be surprised if the Dimarzio designs were all cloned at some point. A lot of those Matsumoku instruments have cream pickups!