Naniwa Chosera Stones
The Chosera-series by Naniwa was the premium line of the assortment. The Naniwa Chosera sharpening stones are ready for immediate use because they do not absorb any water. It is sufficient to wet them. Because the Chosera-line consists of hard sharpening stones they will last for many years. The grit size varies from a Chosera #400 to a Chosera #10000, which can be used to sharpen a very blunt knife into a razor sharp condition. This applies for kitchen knives, pocket knives and knives for outdoor use.
Knife sharpening & maintenance