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(updated 2019: May)

 “Before you clean the dust in a room, you throw water on the floor. 
 Before throwing water on the sharpening stone clean your mind” 
 – Morio Sakamoto
(A message/advice from Mr.Sakamoto to the people
who are sharpening and using his nagura.
– Quote during Florin’s visit to Mr. Sakamoto – see further)

= Nagura

= Nagura toishi = Nagura stone
Production area: 愛知県北設楽郡三輪村
= Aichi prefecture, Kitashitara county/district, Miwa village
Mikawa map 1a.png

= Nagura toishi = Nagura whetstone
中砥石 (nakato) = medium grit stone, tuff stone (凝灰岩),
ash yellow – light yellow (灰黄色・淡黄色)
産地 (production area): 愛知県北設楽郡設楽町
= Aichi prefecture, Kitashitara district, Shitara city
Nagura toishi map 1a1.png


Mikawa nagura 
純三河白名倉砥 = Jun (Jyun) Mikawa Shiro nagura-to
= Pure/Authentic Mikawa white Nagura (whet)stone


検 – 浅野 (red stamp) = Ken – Asano = Examination – Asano
(This Nagura has been officially evaluated, by “Nagayuki Asano”)
Nagayuki Asano 1a
純三河白名倉 = Jun Mikawa Shiro Nagura
= Genuine Mikawa White Nagura
Jun Mikawa Shiro Nagura.jpg

別大上 = Betsu Ōgami = “oversized”
= larger white nagura, mostly square/rectangular shaped
Betsu Ōgami 別大上 1a
特級上 = Tokkyū-jō = Superior class
= larger striped nagura, mostly square/rectangular shaped
別上 = Betsu Jo = Superior grade, white nagura, odd shaped
Betsu jo.jpg
特級 = Tokkyu = High grade, striped nagura, odd shaped


Mikawa Nagura Layers(Thank you Jeremy!)

Classification of Jun Mikawa white Nagura (From shallowest to deepest layer)
(From the book「刃物の見方」”How to view knives” written by ‘Mr. Kōsuke Iwasaki’)
Mikawa 12 layers
①目白 Mejiro
②天上 Tenjou
②天上 Tenjou
③ぶちこう Buchi kō
④コマ(細) Koma
⑤ボタン Botan
⑥八重ボタン Yae-Botan
⑦むし Mushi
⑧アツ Atsu
⑨バン Ban
⑩しきばん Shiki-Ban

In the Mikawa region, Aichi prefecture (Aichi-ken), there are 12 layers in total,
Tenjou has 2 layers, and there is 1 (useless) sand layer.

From shallowest to deepest:

  • 目白 (めじろ) Mejiro = “White Eye”
    Nagura Meijiro.JPG
    Mr. Sakamoto (see further) shared in his interview with
    Florin Pincotan (Zen Razor Japan) that the name Mejiro (white eye) comes
    from the Mejiro bird, also known as the Japanese White-eye bird.
    Mejiro (white eye)
  • 天上 (てんじょう) Tenjou (x2 layers) = “Ceiling”
    The layer of Tenjou nagura was found on the “ceiling” of the tunnel
    (Mr. Sakamoto)
  • (“Serizuna”, some sources don’t refer this layer (kamakura-bori))
  • Buchi kō ぶちこう (a layer which isn’t mined)
  • コマ Koma (= 細名倉, hoso nagura)
    The name Koma (fine) comes from “komakai” (Mr. Sakamoto)
    = “Fine”, said to be the finest Mikawa Shiro Nagura
    nagura-komaTōken-yō Koma Asano Jun Mikawa Nagura.jpg
    刀剣用 = , Tōken-yō (For swords);
    コマ = Koma; 検 – 浅野 = Ken – Asano;
    純三河白名倉 = Jun Mikawa Shiro Nagura
  • ボタン Botan = “Peony flower”,
    a coarse Mikawa Shiro Nagura
    Nagura Botan.jpg
    The small dots on the stone resembles small “peony flowers”
    In Japanese, peony flower is  called “Botan” (Mr. Sakamoto)
    Botan Peony flower 1a.Botan Peony flower 1b
  • 八重ボタン Yae-Botan, a coarse Mikawa Shiro Nagura,
    usually faster & coarser than Botan, sometimes
    has sand layers and quartzite inclusions.
    Yae Botan.jpg
  • むし Mushi
  • アツ (あつ) Atsu (= 中名倉, naka nagura),
    a coarse Mikawa Nagura
  • バン (ばん) Ban
  • Shiki-Ban

MEJIRO 目白 as fine/finer than KOMA コマ?

Mejiro 目白 normally is always been considered as a midrange Mikawa Shiro Nagura,
being finer than Botan ボタン, about equal as Tenjou 天上,  and coarser than Koma コマ.

(update 2019: May)

This doesn’t always seem to be the case…

Florin Pincotan (Zen Razor Japan) shared this very important information with me:

In this video of Alex Gilmore Mr. Sakamoto shows how
he hones a kamisori razor with a Mejiro shiro nagura:

On March 19th (2019) when Florin went to
Mr. Sakamoto, Florin recorded a honing video as well:
Here is the dialogue between Mr. Sakamoto and Florin:
-What is that? Koma nagura?
 He answered:
– No, its Mejiro.
– Why not using koma?
– Because Mejiro is  finer than koma!
– But I knew that koma is finer than Mejiro?!?
– Mejiro is finer, but it doesn’t have cutting power like koma.
– But Koma is more expensive than Mejiro!
– Because it is more rare.
So, there we are!
I’ve tested it myself. At the moment, for me, it is not always clear
if my 特級 (Tokkyu) grade Mejiro 目白 is a bit less fine or finer
than my 特級 Koma コマ, though my 別上 (Betsu Jou) grade Koma
is absolutely finer than my 別上 Mejiro.
I’ve been told of experiences where the HHT results after a
特級 Mejiro vs 別上 Koma were the same! The edge under the
microscope looked better after Koma though. The Mejiro edge
had a more “toothy” appearance.
What seems to be clear is that Mejiro 目白
is absolutely finer than Tenjou 天上!
Please share your own experiences trough this poll!

Is Mejiro finer than Koma? (polls)

(When the Poll isn’t visible, for example on the browser “Brave”, please deactivate the shields, thank you!)

Mr. ‘Sakamoto Misao’ 坂本操 (°1910 – 明治43年), established in 1935 (昭和10年)
the beauty equipment wholesale company “Sakamoto Shokai” 坂本商会 in
Toyohashi city, Aichi prefecture. He repaired and sharpened/polished scissors.

In 1953 (昭和28年), ‘Sakamoto Misao’ knew that Jun Mikawa White Nagura is ideal
for sharpening scissors and razors, he then purchased the Mikawa Nagura mine to be excavated. In 1955 he introduces the Jun Mikawa White Nagura to the beauty industry.

‘Sakamoto Misao’ spread the natural whetstone (Jun Mikawa white Nagura) nationwide, and launched in 1961 a polishing research group with famous people as ‘Kōsuke Iwasaki’ (who was in search for a sharpening stone suitable for a high quality steel steel razor) and others. (1/9 association, Update ’19, Feb).

一九会(いちくかい) = Ichikukai = 1/9 association
昭和36年1月9日に発足, Established on January 9, 1961
Nineteen Meeting
岩崎航介氏 = Mr. ‘Iwasaki Kōsuke’
浅野長幸先生 = Mr. ‘Asano Nagayuki’ sensei (teacher)

The exploitation of the Mikawa nagura stones and a coöperation
with ‘Iwasaki Kōsuke’ 岩崎航介, ‘Iwasaki Shigeyoshi’ 岩崎重義 and
‘Nagayuki Asano’  浅野長幸 (a lecturer at a barbershop) began.

“According to the late Kōsuke Iwasaki, when he first started making
razors he had trouble with honing. He was getting breaks and chips
on his edges, which he eventually found came from the inferior
Nagura that were being sold by the merchants–they were cheap,
and easily found, and of substandard quality. So he began searching
for a long lost source for the Nagura that had been used for centuries
in the polishing of Katana…

He took this selection very seriously; in his book “刃物の見方
(“Understanding Bladed Implements”), he said something along the
lines of: “If a razor maker can not hone a razor well, the razor will
not shave well, and people will think that the razor is no good.”

So he worked on researching just where the best hones, and the best
nagura to use with them, could be found. 

The Junmikawashiro mine (純三河白 …) in Aichi prefecture is the only
place in Japan that produced the Nagura that Iwasaki-san found suitable
for the finest honing and polishing. Not only that, he identified the different
seams of the mine, and with the help of geologist Nagayuki Asano divided
them based on their polishing effects, speed, and purity.”
Mikawa layers

‘Iwasaki Kōsuke’ and ‘Nagayuki Asano’ developed a quality-control system for
grading and authenticating Mikawa Nagura. Each piece was carefully inspected,
and subsequently ink-stamped to qualify the layer and quality of each stone.

Sakamoto Morio 1a
Sakamoto Morio’ 坂本守男 (°1939) inherited the Asano stamps from
his father, ‘Sakamoto Misao’, and he continues to qualify each piece
of Nagura today (純三河名倉).
Sakamoto Morio 1b
Presently (March 2019), ‘Sakamoto Morio’ is 79 years old
(will be 80 this year in October) and still working in his
store in Toyohashi, but relatively soon the Asano stamps
will be passed to his son ‘Sakamoto Kouji’.

The mine was closed in 1976, all ‘new’ Nagura are cut from
large pieces of stock that was mined and stored before then.

Field survey group photograph of ‘Nagura Whetstone’:Mikawa Nagura Iwasaki, Sakamoto, Nagayuki Asano 2a
① 坂本操氏 = Mr.  ‘Sakamoto Misao’
② 浅野長幸氏 = Mr. ‘Asano Nagayuki’
③ 岩崎航介氏 = Mr. ‘Iwasaki Kōsuke’
④ 岩崎重義氏 = Mr. ‘Iwasaki Shigeyoshi’

Mikawa Nagura Iwasaki, Sakamoto, Nagayuki Asano
岩崎航介氏 = Mr. ‘Iwasaki Kōsuke’
岩崎重義氏 = Mr. ‘Iwasaki Shigeyoshi’
浅野長幸先生 = Mr. ‘Asano Nagayuki’ sensei (teacher)
坂本操 = ‘Sakamoto Misao’
SRP/J-Nat club Nagura

The access to Mikawa mine was very difficult, from the road to the
mine entrance is a long and steep way. Because of this they could
make only 3 trips/day to carry the stones from mine to car.
Also, from the mine entrance to the place where the nagura
were found is a 200m long tunnel of approx. 80x80cm tall/wide!

In the same neighbourhood, 三河白, Mikawa Shiro (Mikawa white)
is found, which is a white, compact, tuff stone, used for polishing/finishing
(合砥, 白色・緻密・凝灰岩), the 1 m thick Mikawa Shiro layer is formed
between the bulk of “egg yolk coloured” tuff stone (卵黄色塊状凝灰岩)
産地 (production area): 愛知県南設楽郡鳳来町砥沢
= Aichi prefecture, Minamishitara district, Hōrai city, Tozawa


Hatahoshi nagura:

Hatahoshi Nagura 1a.png.Hatahoshi Nagura 1b
ハタホシ (under 2 flags & star) = Hatahoshi
石銘 = Ishi mei = Stone inscription
本名倉 = Hon Nagura = Original Nagura

Hatahoshi Nagura こま名倉 1a.Hatahoshi Nagura こま名倉 1b.Hatahoshi Nagura こま名倉 1c
Sold as a 1960’s HATAHOSHI NAGURA (7.3㎝x5.5㎝x4.5㎝, 254g )
Stamp/Seal (印) = こま名倉 = Koma Nagura
ハタホシ (under 2 flags & star) = Hatahoshi

Another one:
Hatahoshi Nagura こま名倉 Koma 2a1.Hatahoshi Nagura こま名倉 Koma 2a2.hatahoshi-nagura-e38193e381bee5908de58089-koma-2a3.jpg
Hatahoshi Nagura こま名倉 Koma 2a.Hatahoshi Nagura こま名倉 Koma 2a4.Hatahoshi Nagura こま名倉 Koma 2g2
こま名倉 = Koma Nagura
ハタホシ (under 2 flags & star) = Hatahoshi
正本山 = Shōhonyama
白名倉 = Shiro Nagura

It is not clear what the meaning is of 白名倉 (Shiro Nagura),
especially because it stands together on the stone with こま (Koma).

So it doesn’t have an association with 目白 (Mejiro).
It does remind me at a rare Iwasaki nagura:
Mikawa Shiro Nagura:
Mikawa Shiro Nagura Iwasaki 岩崎選 白名倉 1a1
岩崎選 = Iwasaki-sen = Iwasaki Selection
白名倉 = Shiro nagura = White nagura
Perhaps they were mined and stamped before the 1960’s,
where maybe 白名倉 became 純三河白名倉??? (not sure!)
Or, maybe they were mined in Tozawa (Aichi prefecture, Minamishitara
district, Hōrai city), which, as previously mentioned, is nearby Miwa village,
where 純三河白名倉砥 were mined. The stones, mined in Tozawa, were called
三河白, Mikawa Shiro (Mikawa white), a white, compact, tuff stone, used for polishing/finishing…
Again, I’m not sure if these are such stones…

Talking about Iwasaki, here is a stone with both Iwasaki and Maruka (Hatanaka) marks:

  • Tomo nagura:
    X, Stones Tomo 1a X, Stones Tomo 1bX, Stones Tomo 1c X, Stones Tomo 1e
    X, Stones Tomo 1c1 X, Stones Tomo 1e1
    (?)本用 = (?) Hon yō
    共ナグラ用 = kyō Nagura-yō = Use as tomo Nagura (?)
    ㋕正本山 = Maruka Shō Honyama (Nakayama)
    小型本山 = Kogata Honyama = Small size Honyama
    TRADE㊂Mark 三条製作所 = Sanjō seisakusho = Sanjō factory
    Blue stamps:
    ㋕正本山 = Maruka shō Honyama (Nakayama)
    純眞正本山 = Jun shin shō honyama (honzan)
    = Pure Authentic Honyama (Nakayama)

→ Also see “Iwasaki“, chapter: “Stones”


= Tsushima
= Tsushima kuro nagura to = Tsushima Black nagura stone
Quarried on Tsushima island, west of Nagasaki.
This medium grit whetstone produces slurry which breaks down very finely.
Tsushima is mined from the mountain & underwater (in the ocean).
Tsushima map 1a
Tsushima map 1b.png

= Gujō to, a less known stone which can be used as a nagura (名倉)
Gujō to 1a 2.jpg 郡上名倉 = Gujō nagura
Symbol in cicle = 鶉 (うずら, ‘quail’)
中砥石 (nakato) = medium grit stone
(quartz porphyrites penetrating the granite)
産地 (production area): 岐阜県吉城郡神岡町伊西
= Gifu prefecture, Yoshiki district, Kamioka city, Inishi
Gujō map 1a
Gujo Nagura originally is said to be used for finishing (with mirror finish),
although not as famous as the Mikawa nagura.

Here is a place they can be bought:
Gujo Natural Nagura Stone, ‘Dieter Schmid’s Fine Tools’

This entry was posted in HISTORY & IDENTIFICATION. Bookmark the permalink.

10 Responses to Nagura

  1. One of the biggest problems for anyone in the United States who is trying to get into Japanese natural whetstones is obtaining reliable and consistent information in a language that they can read. Most of the ignorance is based on this problem. I, for one, am an avid researcher and have been doing research on a variety of subjects for many years, and I have never found a harder subject to learn about due to the sheer lack of sources. This article is a wonderful step in the right direction and everything written is very helpful.

    Liked by 1 person

  2. Pingback: “Nakato” → “Shiage toishi” | Fikira

  3. Pingback: Japanese Natural Stones, Kanji & Information | Fikira

  4. Gregory Burris says:

    Thank you so much! Fascinating! Just got my first stones. Nakayama kita , ozuku tomae. Thanks for sharing! Greg B.

    Sent from Yahoo Mail on Android


  5. brooksie967 says:

    Nice post. This image of the layers of nagura might be helpful to add to your data.


  6. Jeremy Brooks says:

    I’m not sure if this is helpful or not but I have a picture of the layers, labeled, that I didn’t see included on your page. Hope it helps

    Sent from Mail for Windows 10



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