Kyoto-made, details unknown, Tomae Midori-ita (Green Plate). As a natural whetstone from Kyoto, it has a rare level of fineness, giving the impression of a fine finish or a medium finish. It's a hard stone, easy to sharpen with, and provides a good finish without the tendency to drag the steel. The seller's comment at the time of purchase described it as a super-hard stone for final finishing, which is quite a different impression. This whetstone may be one where the results vary depending on the type of blade and sharpening technique used.