A kata is a pattern or form used for study or reference when creating an utsushi blade. The exercise of accurately making kata based on the work of historical smiths is an excellent way to train the eyes, mind, and body to create proper forms. This particular kata is based on a beautiful tanto made by Shintogo Kunimitsu, known as Aizu Shintogo. He created the Midare Shintogo, the first blade in the Soshu-den (Sagami) tradition, is known as one of the best swordsmiths to have ever lived and a master of the tanto. He did his work in the late 13th century (Kamakura) and is acknowledged as master to Masamune, one of the most famous swordsmiths in Japan. Kunimitsu is recognized for his beautiful tanto and a careful study of his work is a great foundation for designs that are aesthetically pleasing and authentic.
I admire Kunimitsu for his fusion style approach to swordsmithing. Though there is some ambiguity surrounding the exact details of the story, it is held that, taking his foundation from the Awataguchi School of Kyoto where he studied, Kunimitsu relocated, developed his own style, and was one of the founders of the Soshu tradition. Another interesting thread for me is the connection between Kunimitsu and Munechika via the Yamashiro style.
Making a kata is not as difficult as making an actual blade for several reasons. One is that the outline is the only concern as the bevels are not created for kata. Another is that the raw material need not be as thick as is would for a tanto, 1.5mm is enough. And the final reason is that there is no tempering involved as the steel need only be mild and not high carbon. The most important aspect of making kata is to be very accurate and as true to the original lines as possible.
The primary difficulty can be finding patterns that have measurements so they can be enlarged to the actual size. Books with quality oshigata are one place to start from. I obtained this pattern from the soulsmith Pierre, he has a growing collection of scaled patterns available for download in his resource area as well as precision cut kata available for study. He also has more information on scaling and making kata.
I have had this particular pattern on file for several years and have continually had the printed image visible at my desk for pondering. I finally had the opportunity to make it into a kata a few weeks ago when I was working on another project and the steel turned out to be the wrong dimension and folded over as it was forged. Rather than waste it I decided to turn it into a kata while it was in the fire. Unfortunately I did not have the pattern with me at the workshop so I had to forge as near I could by memory, knowing the approximate blade length and width at the machi.
My initial attempt was quite close and only required a bit of filing to clean up the blade, proof that careful study of good examples can be internalized to a great degree. I had left the tang half forged for fear of taking too much of the blade away and finished it on the next trip to the workshop. I plan to use this kata for a project in the near future, in the meantime I am glad to finally have a physical kata to study and ponder.
Specifications of the Original Tanto
Nagasa: 8 Sun 4 Bu (253.7mm)
Motohaba: 9 Bu (27.3mm)
Motokasane: 2 Bu 4 Rin (7.3mm) – worn
Nakago: 3 Sun 6 Bu (108.7mm)
Construction: hira-zukuri, mitsu-mune
Sori: straight/slight uchizori
Steel Appearance: Itame, mokume mixed with strong ji-nie and chikei
Hamon: Chu-suguha in ko-nie, ko-maru sagari, long kaeri, slight hakikake ?
Nakago: Ubu, one mekugi-ana, signed near the middle
Mei: Kunimitsu (another fine example | info about his steel | more examples of his work | info on the soshu school)
= 0.1 shaku（尺）
= 1 sun（寸）
= 10 bu（分）
= 100 rin（厘）