Impressive And Interesting Kodachi

[Gakusee]

Saw this sword recently on Aoi’s website.

https://www.aoijapan.com/katana-ko-bizen-nobufusa-saku-63rd-nbthk-juyo-paper/

 

Not commenting on the price (no comments needed there), but wanted to point out the tight and well forged jihada and hamon. There were some other threads about KoBizen vs Yamashiro hada and hamon and I would like to draw arrention to the similarities between the two in this blade here. As observed elsewhere on the board, back at the end of Heian and beginning of Kamakura there were a lot of similarities between Awataguchi, Sanjo, KoBizen. The hack is very well preserved despite the age.

 

The Nobufusa name is known among smiths working in the Ko-Bizen and Ko-Ichimonji groups since very early times. According to the historical book Kokon Meizukushi Taizen, the two kanji signature Nobufusa is from the Ko-Bizen school, and the three kanji mei Nobufusa saku is from the Ko-Ichimonji school. But the argument continues still as to which signature belongs to which period. Regardless, that nakago and mei are ancient and precious.

 

Finally, Aoi has started to venture more in the top end of the market, beyond its mid market mainstay.... interesting....

[Curran]

Hi Michael,

 

If okay to hijack the thread a wee bit, I'd like to ask about the oshigata and white line from the hamachi point. It is more prevalent on one side than the other.

 

Two senior North American collectors in Tampa recently interpreted this as mizukage. Yet the line is not hard and straight edged as is textbook depicted, and it is unlike the mizukage I have seen on full retempers.  Rather here it curves away and disappears quickly. Most of the jigane is fine to excellent in the blades, though the temper line from the hamachi always seems to be straight for 1.5 to 3 inches before whatever choiji or other temper pattern seen up the rest of the blade.

 

I have seen this a lot in Bizen swords up into the muromachi period. Flipping through the Ichimonji book, there it is again on pg 12, pg 17, and pg 25. If I went further, probably I can list a few more.

As with the Bizen blade in Tampa, most of the jigane is good to excellent in the blades, though the temper line from the hamachi always seems to be straight for 1.5 to 3 inches before whatever choiji or other temper pattern seen up the rest of the blade.

 

What is this? The result of some old way of moving up the hamachi?

All the blades I have seen with this have been papered, so it has to be something the Japanese papering authorities recognize and could explain.

[Ray Singer]

Curran, I believe that what you were seeing is the natural starting point for the utsuri. If I remember correctly this is discussed in Nakahara.

[Blazeaglory]

Amazing! Great condition as well!

[Ted Tenold]

Bear in mind that the blade has undergone a number of polishings, during which material is removed and the effects of heat treating are stronger and more defined at the surface than toward the heart of the sword where it becomes diminished and thus changes from its original shape and character.  Features such as utsuri are also not always symmetrical from omote to ura, and will often vary in form, consistency, and intensity.  

 

If the oshigata is drawn faithful to the blade, I would disagree in calling this "mizukage" which is more or less a perjorative term associated with  saiba (saiha), "re-tempering".  Origin of utsuri is very commonly seen in ubu blades to arise in advance of or at origin of the yakiba, up into the ji of the sword and then curve to advance along the lenght.  Mizukage is a hard 45 degree-ish line that directs from the has side of the sword and up and off the mune.  Two distinctly different visual elements.  

 

This sword has been ranked Juyo.  If it hasn't been remarked as Yakinaoshi (which is somewhat forgivable for Juyo in Nambokucho and earlier), then it's not mizukage.  It's utsuri.  

[Curran]

B- Mizukage is a hard 45 degree-ish line that directs from the has side of the sword and up and off the mune.  Two distinctly different visual elements.  

 

 

Yes- hard 45 degree-ish line. Kinda hard to get anything else when dunking in water.

Surface tension isn't exactly going to bend it that much.

 

I don't have the Nakahara book anymore. So the natural start point of the utsuri moves up to the hamachi point each time it is moved up?

Ray- on the Aoi Arts sword, on one side the whiteish mist line seems to do a boomerang U turn backwards before traveling up a bit. I admit I have never drawn a full sword oshigata before. I find it confusing. Then again, I don't know what is going on with the example on page 22 of the Ichimonji book. That cannot be rendering of utsuri there, starting at the hamachi.

 

The two Japanese gentlemen (Kodama-san and Kunio-san?) who taught for the NYC, explained that a early technique to move up the hamachi up to a point was to heated block of (copper or other highly conductive metal)  to 'soften' the point of cutting. They explained this old technique had a few other effects- like a bit of mist temper and slight masame near the area, but that it was a choice to lower risk of damaging the sword.

       Yet it seems an idea alien or contrary to many westerner collectors. I'm hoping Ted can weigh in on this one, as he has got the technical expertise to say whether the older NYC club teachers were serious or making it up.

[Gakusee]

Curran, I have read the same about softening through copper blocks. Cannot remember where.

 

Now, on the point of mizukage. We tend to interpret it negatively in the West (as often it could be a sign of sauna) but often it is a corollary of quenching (not too deeply) and is viewed by the NBTHK and other experts as normal in some of the ancient blades as illustrated below.

 

Markus Sesko, Koto Kantei:

 

“Along the ha-machi often a mizukage-like utsuri appears which connects to the „regular“ utsuri. This is also one of Kunitsuna´s typical features. (This is especially noticeable at the gyobutsu Onimaru-Kunitsuna and is sometimes called „koshiba“ but this is in a strict sense incorrect. Incidentally, the Kokon-mei-zukushi“ [古今銘尽] writes on Kunitsuna: „A koshiba appears about 1 sun [~ 3 cm] above the habaki. The ha is narrow before this koshiba [i.e. right at the ha-machi]. In addition, the jiba appears somewhat smoky in this area.“ It is assumed that this entry refers just to the Onimaru but when we reconstruct the kantei blade to its original condition, it might had shown the very same characteristics.)”

 

“The mentioned large itame-mokume mix, prominent ha-nie, hotsure and yubashiri along the habuchi and a mizukage-like appearence at the base can be seen on Ko-Hōki works. “

 

“Incidentally, such a mizukage is often found on works of No-Sada and can be regarded as one of his characteristics.”

 

 

Honma sensei, Nihon Koto Shi:

“The other in Bizen style resembles to the work of the Ko-Ichimonji school but the start of the hamon tends to be

yakiotoshi then mizukage appears on the ji and the hamon consists of subdued nioi accompanied with a little weak nioi-guchi” when talking about Gotoba and one of his forging styles..

 

So my observation is that they often call mizukage this particular effect of quenching, where utsuri might or might not also start, at 45 degrees at the hamachi but above all it is not derogatory for certain schools.

 

 

Regarding this particular blade:

- the shadow is soft and diffused and not like the illustrations of saiha mizukage I have seen in books

- the nioiguchi seems very well controlled and tight; I would have thought it would have suffered during saiha if it were the case

- the Zulu Nado text about this particular blade is quite complimentary and talks about the high quality and how rare this tachi is

[paulb]

Michael

Picking up on one of your earlier points I think this supports the idea previously discussed regarding similarities between the early schools, Munechika, Hoki, Ko-Bizen etc. We have seen in the past attributions of mumei work jump between Ko-Bizen and Ko-Ichimonji. Also smiths being repostioned from one school to another. At Samurai art expo last year there were examples of both and I for one would be very hard put to distinguish between them at a kantei.

 

When I saw Nobufusa I immediately jumped to Ichimonji not realising the name was also associated with Ko-Bizen

 

Re Mizukage it is certainly mentioned regularly as a feature of early work. I also have a very clear example on a shin-shinto piece that shows absolutely no other signs of saiha so I assume it was part of the original hardening.

As you say the western view has become a little too suspicious of the feature always associating it with rehardenning which is not the case.

It reminds me of the western view of the term "Den" but that's a whole other topic much covered before.

[Tom Darling]

Am i looking at a ko-Bizen sword? It's not koshi-zori, width should be narrow, ubu nakago has no funbari nor ko kissaki or is it ko maru  with slight return. Don't care for the bonji,either. Now, I must say that i could be wrong, am i? I have held five Ko-Bizen blades and owned three. IMHO.  Thank you.

 

Tom D.

[paulb]

Well according to the NBTHK Juyo committee you are looking at a Ko-Bizen sword and they have had the advantage of seeing it in hand rather than on a computer screen. Based on that alone I think you are wrong. 

I wonder if the variations from the features you were expecting are due to changes caused by polishes or adjustments over the years. Also it is a small sword (relatively) a Ko-dachi and perhaps that is why the sugata is different from what you have seen in other blades. I agree with you about the Bonji and would much prefer it not to be there. I would guess (but I am not sure why) that this might be a later addition.

As Michael mentioned earlier I think with very early blades the features we identify with the Gokaden are not fully established and you see many similarities between the different traditions. 

[Gakusee]

Tom D

 

The blade has a very clear koshizori and a clear ko-kissaki.

 

The NBTHK have probably looked at the mei and compared it to genuine mei they have examined and considering the possibilities (KoBizen or KoIchimonji) might or might not have leaned one way or the other and here it is closer to KoBizen by implication, even though in the headline they did not says clearly KoBizen (so they left a little door ajar).

 

Now, I agree that it is a bit unusual for KoBizen (I would have expected a tad more nie-driven hamon hataraki and a less controlled hamon). However, here the choice is between KoBizen and KoIchimonji, so on balance one could possibly say KoBizen since KoIchimonji would/should have more kochoji formations. Also, the shape looks a bit older, however, it could be a crossover or transition blade at the cusp of Heian into early Kamakura. I think the Zufu paper talks about this being an older blade and at least three times mentions KoBizen (I did not see a single time they used KoIchimonji in its paper).

 

Of course, then you have two great authorities writing in their sayagaki that it is KoBizen. Who are we to challenge the authority of a Honami and Tanobe sensei plus the independent opinion of the current NBTHK (as the Juyo certificate dates back to 2017, when Tanobe sensei has already retired)?

 

To take it a scientific step further. KoBizen as a term is used for blades forged from the 980s/990s to the 1230s. As we know this is a period of well over 200 years. Towards the beginning of that period blades were more rustic and wilder (like koHoki) and towards the end - more like koIchimonji, and koIchimonji originated from KoBizen. So, it is very difficult to be dogmatic and draw the line precisely and say that a blade does not look like the standard for the simple reason that the standard was fluid and evolved over 200 years.

 

We have also handled various KoBizen blades and hopefully will one day be able to have one (you are fortunate to have owned three - positively envious!). In my observations I have seen a rustic Tomonari, a more elaborate (later Tomonari), an even more sophisticated Masatsune (x2) and then various KoBizen which at first glance looked like Ichimonji. In fact, one of the blades I liked most at Kurokawa san was a KoBizen which was so actively laden with choji that I thought it looked like Fukuoka Ichimonji. And yet there I have also seen a great KoBizen blade at his place which looked like a Masamune or another high grade Soshu. I was really embarrassed when I said Soshu and he told me KoBizen but then he smiled and explained many people had said the same as me.

[Gakusee]

In reference to Tom’s comment, I forgot to mention that the blade has a very clear funbari, in addition to the koshizori and kokissaki, so actually the shape is rather archetypal.

 

Anyway, it is good to engage in some debate as above.

[Tom Darling]

Hi Michael,

 

Indeed, it's impregnated with a peculiar flavour. Kurakawa san is, The Daimyo in Tokyo.

 

Regards,

 

Tom D.