Komon - Natural Stone - Uchigumori (No. 002)

Hitohira sources a large variety of high quality stones, offering you a wide range of price points, uses, and skill levels. Not only does Hitohira provide classic Kyoto-based stones, they also procure stones that originate from all over Japan, giving you a opportunity to use some less common stones. So whether you're getting your very first natural stone, or are searching for that perfect piece to round-out a progression, Hitohira likely has you covered.

Most stones are graded by their in-house polisher, but are otherwise graded by Strata.

Brand: Hitohira ひとひら (一片)
Producing Area: Kyoto, Kyoto Prefecture - Japan
Mine: Nakayama 
Strata/um: 
Appearance: What may seem initially unremarkable, in fact contains some stellar renge patches intermixed with beautiful, deep yake when wet.
Size: 206mm x 82mm x 25mm
Weight: 918g
Est. Grit: 6000-8000

1-5 Scale: 1 = Less, 5 = More
Hardness Level: 4.5
Scratch Depth: 1.5
Speed: 3.5
Wear Rate: 4.5
Self Slurry: 1.5
Thirst: 2
Consistency: 4.5
Feedback: 2
Ease of Use: 3

Recommended Uses: Very keen edges; ura; glossy kasumi; microbevels; push-cut tools; razors

Notes: This is a "very" stone — very fast for its hardness; very fine scratch pattern that yields very bright and even kasumi, very consistent feedback, very keen results on edges and ideal for push cut tools and razors. It's great to see newly mined Nakayama stones hit the market every now and then. The only note would be that since it's hard, you will need to be mindful of your pressure. Using a nagura or forcing a slurry can help a lot in adding "cushion" between the blade and the stone.

Please Note: Given the natural aspect of these stones, all graded characteristics are our own subjective thoughts which may vary from your expectations and assessment. The images shown and characteristics described may be from a previous, random example, or when first measured before being tested numerous times. If purchased, yours may differ slightly in appearance and qualities.

Hitohira sources a large variety of high quality stones, offering you a wide range of price points, uses, and skill levels. Not only does Hitohira provide classic Kyoto-based stones, they also procure stones that originate from all over Japan, giving you a opportunity to use some less common stones. So whether you're getting your very first natural stone, or are searching for that perfect piece to round-out a progression, Hitohira likely has you covered.

Most stones are graded by their in-house polisher, but are otherwise graded by Strata.

Brand: Hitohira ひとひら (一片)
Producing Area: Kyoto, Kyoto Prefecture - Japan
Mine: Okunomon
Strata: Tomae?
Appearance: Asagi surface when dry, but nice scattering and zones of Ao and Aka Renge with some purple and red splotches when wet
Size: 204mm x 76.6mm x 38.9mm
Weight: 1394g
Grit Range: 3000-5000

HITOHIRA'S GRADING
1-5 Scale: 1 = Less, 5 = More
Hardness: 3.7
Grain Scale: 3
Sharpening Speed: 3.9

Recommended Usage: Kitchen knife (edge); kitchen knife (bevel); Hagane polish; Chisel, plane.

Notes: Very strong grinding power. Manageable hardness. Easy to use.

Please Note: Given the natural aspect of these stones, all graded characteristics are our own subjective thoughts which may vary from your expectations and assessment. The images shown and characteristics described may be from a previous, random example, or when first measured before being tested numerous times. If purchased, yours may differ slightly in appearance and qualities.

One of our most trusted sources handpicks these stones from the famed Imanishi in Kyoto for us, spending hours testing dozens and dozens and selecting only the best of the best at a variety of price points. These tennen toishi represent some of the best value you will find on the market for natural stones.

These stones are so impressive that they often make you feel like you are "cheating", so to speak - they provide outstanding results at a speed seemingly found only in stones that cost many times more, all while being fun and easy to use - they make it seem as if you have learned years of polishing in a matter of minutes. Combining these gems with the correct steel, you will come to understand the beautiful harmony skilled polishers sometimes have difficulty describing - working on natural stones with well-made knives truly ties the whole subject together.

We are proud to provide such wonderful pieces to you!

Brand: Komon-picked Imanishi
Producing Area: Kyoto 
Mine: Hideriyama
Appearance: Asagi green with streaks of Namazu
Size: 2,567g
Weight: 238mm x 75mm x 73mm
~Grit Range: 3000-5000

1-5 Scale: 1 = Less, 5 = More
Hardness Level: 2.5
Scratch Depth: 2.5
Speed: 4
Wear Rate: 3
Self Slurry: 4
Thirst: 3.5
Consistency: 5
Feedback: 3
Ease of Use: 4

Notes: An extremely rare vintage Hideriyama, especially in this large format. A true pleasure to use — it offers silky feedback with a slurry that develops quickly and yields an exceptionally consistent scratch pattern. The resulting kasumi finish is warm and rich and can be achieved with ease and speed. Depending on your approach, you can stop early for a hazy-to-frosty kasumi, or continue on in your polishing sequence for a brighter finish.

Thanks to its generous surface area and substantial thickness, this stone will provide years of use. However, as it’s not particularly hard (though not overly soft either), it’s important to work the surface evenly to avoid localized dishing. It’s likely too soft for push-cut tools, but perfect for wide bevel polishing, even convex grinds.

This is an outstanding stone for collectors due to its rarity, quality, and vintage provenance. While best suited for intermediate to advanced users, its forgiving nature also makes it accessible to mindful beginners.

Recommended Usage: Hazy to frost kasumi, pre or pre pre polisher, convex grinds, refined but textured edges.

Disclaimer: Given the natural aspect of these stones, all graded characteristics are our own subjective thoughts which may vary from your expectations and assessment. The images shown and characteristics described may be from a previous, random example, or when first measured before being tested numerous times. If purchased, yours may differ slightly in appearance and qualities. All stone sales are final.

One of our most trusted sources handpicks these stones from the famed Imanishi in Kyoto for us, spending hours testing dozens and dozens and selecting only the best of the best at a variety of price points. These tennen toishi represent some of the highest quality you will find on the market for natural stones.

These stones are so impressive that they often make you feel like you are "cheating", so to speak - they provide outstanding results at a speed seemingly found only in stones that cost many times more, all while being fun and easy to use - they make it seem as if you have learned years of polishing in a matter of minutes. Combining these gems with the correct steel, you will come to understand the beautiful harmony skilled polishers sometimes have difficulty describing - working on natural stones with well-made knives truly ties the whole subject together.

Because each stone is tested extensively by Komon before they are sent to us, we honor their notes and grading system listed below.

We are proud to provide such wonderful pieces to you!

Stone: Ohira Suita
SKU: 260303-Ohirasuita
Size: 206mm x 75mm x 49.5mm
Area: Kyoto
Mine: Ohira
Layer: Suita
Grit: 6,000-8,000

Hardness: Medium
Finesse: Fine
Cutting Speed: Fast
East of Use: Medium

Recommended Use: Best suited for kitchen knives and Japanese wood working tools, single and double bevel iron clad carbon steel.

Interpretation of the Stone: This Ohira Suita was overall a very fine stone with strong cutting speed, making it very easy to transition from a 3K synthetic stone. This Ohira Suita is on the finer side, bringing up detail in iron cladding. Best used with very little water to start the stone and polishing process. Also worked well with a slurry from a a very worn 1500 atoma to make a very fine mud. Tested on Tanaka blue 1 sanmai, Tamahagane and wrought iron with excellent results, good feedback. On white 1 Honyaki, due to the stone's fine texture, honyaki can be a bit challenging, but doable. The edge produced from this stone was very crisp yet fine.

Authenticated On/By: Ivan Fonseca 03/16/2026

One of our most trusted sources handpicks these stones from the famed Imanishi in Kyoto for us, spending hours testing dozens upon dozens and selecting only the best of the best across a variety of price points. These tennen toishi represent some of the highest quality natural stones you will find on the market.

When combined with the correct steel, using these gems help you understand the beautiful harmony between stones and steel that skilled polishers sometimes have difficulty describing in words. Working on natural stones with well-made knives truly ties the entire subject together. We are proud to provide such wonderful pieces to you!

Because each stone is tested extensively by Komon before being sent to us, we honor their notes and grading system, which we have listed below.

Stone: Uchigumori
SKU: 251001-UCHI-1
Size: 270mm x 70mm x 30mm
Area: Kyoto, Kyoto Prefecture - Japan
Mine: Ohira
Layer: Uchigumori
Est. Grit: 6000-8000

Hardness: Medium
Fineness: Fine
Cutting Speed: Fast
Ease of Use: Easy

Recommended Use: Excellent for both hard and soft steel, soft cladding, wrought iron.

Interpretation of the Stone: A very smooth, soft, fast-cutting Uchigumori with light karasu patterning throughout one end. This stone is especially easy to use, even on difficult or harder honyaki, and performs exceptionally well on Hitachi and similar steels, as well as harder tamahagane, modern tamahagane, and related materials. It is a very uniform and smooth stone that provides excellent feedback.

It was tested on tamahagane, honyaki, Hitachi honyaki, vintage steels, as well as Hitachi steels forged by Tanaka. It performed excellently across the board on all steel types and forging styles it was tested with, offering smooth cutting performance and excellent ease of use. It worked exceptionally well on single-bevel knives, both clad and honyaki.

Comes with Tomo Nagura

Authenticated On/By: Ivan Fonseca 03/14/2026