Natural stones

This is Nakayama Suita from the Kato mine.As it is a relatively hard stone, we recommend using it with slurry.However, if you're not careful during use, it may leave scratches

It tends to produce a kasumi finish.While it is, of course, suitable for sharpening blades, its slim form also makes it useful for generating slurry.

This whetstone tends to bring out a slight sheen on the steel.While it is, of course, suitable for sharpening blades, its slim form also makes it useful for generating slurry.

This is a soft whetstone that produces a generous amount of slurry.While it is, of course, suitable for sharpening blades, its slim form also makes it useful for generating slurry.

The current whetstone-producing mountain is called Mizunashi-yama.Adjacent to it is a peak known as Kokuzō-mine, named after the deity Kokūzō Bosatsu, who was once enshrined there.
Kokūzō-grade Iyo whetstones are typically gray-brown with a plain appearance, but they evoke the feeling of having sealed in a piece of the eternal natural world—as if a fragment of the void itself were cut and captured.
They are extremely hard and often have a very fine grain.When used with a diamond plate or a Nagura stone, they can produce an exceptionally smooth edge, functioning effectively as a medium-finishing stone.

Although similar in appearance to Kokūzō Black, this stone tends to bring out a faint sheen on the blade during finishing.

Among the various routes historically used to transport Iyo whetstones from the quarry to the port, one mountain pass is now known as the Nanaore area.
The name “Nanaore” likely originates from the winding, twisting nature of the mountain roads in the area.
The region is also known for its thriving plum cultivation. The plums grown here are called Nanaore Koume and are considered a specialty product of Tobe Town.
The Iyo Meito whetstone called 「Koume」 draws its name from this connection. It features fine crack patterns across its surface, which are reminiscent of plum branches stretching and blooming along the historic paths once used to carry whetstones.
This stone was quarried in the past from a site known for producing top-grade material. It offers a sharpening feel similar to that of Shiroto, a premium white-grade whetstone, and typically has a very fine grain.

It is a hard stone, and as a medium-finishing whetstone, it tends to leave a misty, subdued finish on the blade.

Its surface features a beautiful mottled brown pattern, reminiscent of autumn foliage on the whetstone mountain.

The stone is extremely hard and typically has a very fine grain. When used with a diamond plate or a Nagura stone, it can produce an exceptionally smooth edge, functioning effectively as a medium-finishing whetstone.

It is a relatively hard stone. The finished edge tends to have a soft, faint glow　resembling the gentle flicker of a firefly’s light.

Although this whetstone contains some pinhole, they do not interfere with sharpening, and it offers smooth contact with the blade.

Many stones of this type offer a sharpening feel similar to those known as Koume or Raijin.
The orange gradation resembles the slanting rays of the setting sun coloring the evening clouds.
They tend to be fine-grained, with a hardness ranging from slightly soft to medium. Extremely rare,
these stones are like natural miracles born from the earth.
Although they contain pinhole, they do not interfere with sharpening,
offering a smooth and consistent feel against the blade.

The current whetstone-producing mountain is called Mizunashi-yama.
Next to it lies a peak known as Kokuzō-mine, named after Kokūzō Bosatsu,
who was once enshrined there.
The Kokūzō-grade Iyo whetstone is plain in appearance, with a gray-brown tone,
yet it feels as though a piece of the vast, eternal natural world has been sealed within
a fragment of the void itself captured in stone. It is extremely hard and typically has a very fine grain.
When used with a diamond plate or a Nagura stone, it can produce an exceptionally smooth edge,
functioning well as a medium-finishing whetstone. Its appearance is rugged,
and its sharpening feel is honest and straightforward.
It may be stern in character, but it’s a whetstone you can truly rely on.

Grain and plain—each side offers a different feel.A slightly unusual whetstone that lets you enjoy two distinct sharpening experiences in a single stone.

Several shiki (horizontal mine shafts) once dug into the whetstone mountains still remain today.
The stones extracted from these tunnels often differ somewhat from those quarried by open-pit methods.
Among them is a stone with an appearance so unique it defies description
these are known as Ryūjin ("dragon god") stones.
Most of the old shiki tunnels have since collapsed and are now sealed off due to deterioration.
The place, once described as "minoke mo yotateri"—a phrase expressing a chill that runs down the spine
still holds the spirit of those who risked their lives for whetstone mining and the deep history of 1,300 years of Iyo-to tradition.
As whetstones, these are extremely hard and typically have a very fine grain.
Using a diamond plate or a Nagura stone is recommended, and they function well as medium-finishing whetstones.

Depending on whether you generate slurry at the beginning or not, the sharpening feel and finish can change dramatically.

The semi-natural whetstone “Takuma” is composed of approximately 90% natural Iyo Toishi stone material and is kiln-fired into shape.

Natural whetstones are products of nature, so their sizes may vary.
Thank you for your understanding.

Esteemed by Kyoto craftsmen for generations,
this whetstone is now a rare gem, seldom found on the market.
It pairs beautifully with finely forged blades.

For a natural whetstone, it offers excellent sharpening power.Highly recommended for those who wish to refine the appearance of their blades or seek the unique sharpness that only natural stones can provide.

For a natural whetstone, it offers excellent sharpening power.Highly recommended for those who wish to refine the appearance of their blades or seek the unique sharpness that only natural stones can provide.

For a natural whetstone, it offers excellent sharpening power.Highly recommended for those who wish to refine the appearance of their blades or seek the unique sharpness that only natural stones can provide.

This is a relatively soft whetstone, known for its ability to produce a beautiful finish on both the soft carbon and the cutting edge.Perfect for those who care about the visual appearance of their blades.

If you press too hard while sharpening, it may leave scratches on the surface.However, if you sharpen gently, as if letting the blade float, it will produce a beautiful finish.