This is a natural finishing stone from the Nakayama Kurumaguchi line.

Kurumaguchi is regarded as one of the most highly respected mining entrances within the Nakayama mine and has long been prized for applications requiring delicate and highly refined edge work, such as straight razors, woodworking tools, and honyaki knives. Stones quarried from the central section of the tunnel are generally considered the finest examples, and this Asagi stone is believed to have originated from an area extremely close to that highly prized central zone.

Despite its compact size, this stone is exceptionally dense and fully embodies the refined sharpening characteristics for which Kurumaguchi stones are renowned. It offers outstanding edge engagement and excellent tactile feedback, allowing precise control throughout the sharpening process. Water absorption is moderate, and it generates a fine, easily controlled slurry that helps produce an exceptionally keen and refined edge. Its outstanding quality becomes immediately apparent from the very first stroke.

The finished edge is not only exceptionally sharp, but also develops a bright, lustrous kasumi finish that beautifully balances cutting performance with visual elegance. It is particularly well suited for straight razors and blades made from high-hardness steels.

Unfortunately, a small portion of the sharpening surface has been chipped, and a crack is visible along one side of the stone. For this reason, it is being offered at a reduced price. As a precaution to enhance stability, the side of the stone has been generously sealed with Cashew lacquer.

Even with these cosmetic imperfections, this stone fully delivers the refined sharpening experience that has made Nakayama Kurumaguchi one of the most highly regarded names among natural whetstone enthusiasts for generations.

Please note that these are not for beginner sharpeners since they're harder to use.These are natural stones meaning that every single one of them are different so my measured size are not accurate. This is a life time investment for people who lives sharpening their  tools, do not hesitate to ask me your questions.”