Quote Originally Posted by JimR View Post

Here are the some possible explanations I have come up with.
1. They feel that since the American market is bigger, it might be more willing to pay a bit more for the slightly higher grit (unlikely--Japanese tool users are VERY willing to pay high prices for quality...).
2. The Shapton stones are, in fact, identical but there is a difference in grit rating in the US making a Japanese 10,000 equal to an American 12,000; 12,000 to 15,000 etc. (JImmyHAD, who is experienced in these things like I never will be, says they are different.) This would also be unlikely, since the other stones have the same numbers...
3. The Shapton stones are identical, and they're just saying it for some weird reason that we Westerners could never understand. Probably something to do with Ninjas.

I go with number 3. Though none of this explains the Naniwa stones....because they still have a 10,000 in the States, right?

Soooo...what have I missed?
I agree with number three. I don't have any reason, I'll just pick any answer with ninjas in it. All they do is flip out and kill people! They're totally sweet.