I just had a PM asking about the differences between Shapton's Pro stones sold in Japan vs those sold in the US, here's the reply I gave....
Shapton Pro = Kuromaku
After much debate over many years I'm 100% certain in my mind that the Shapton Pro stones are the same the world over. The only difference between Japanese & US versions is the marketing hype. I'd need to have a chemical analysis to prove this otherwise.
They work and behave identical in every way shape and form to each other and there's not a soul I've talked to, who has used both versions, who say otherwise.....well except for the US distributor and some US vendors.....so take that for whatever it's worth.
IMO the 12k JP version is the same as the 15k US version.
IMO the $650 US 30k is the same as the $250 JP 30k.