Shobu Zukuri Nagamaki
At first glance it appears to be a shobu zukuri sugata but nakahara states in his book that this is a questionable classification.
Shobu zukuri nagamaki. Reason being that the shinogi does not continue into the tip but upward to the back of the blade. Shobu zukuri is usually found in tanto and wakizashi forms more often than katana and has evolved from styles normally used in naginata and nagamaki. Off course there are exemptions. Normally its tsuba is very small with the same diameter as its seppa.
Shobu zukuri naginata naoshi nagasa 43 cm oroshigane san mai zubu yaki hardening ichimonji style. So if it isn t a shobu zukuri is it a nagamaki naoshi instead. One sugata that you may be aware of is called shobu zukuri. Naginata nagamaki naginata naginata is a long handled single cutting edged blade.
A naginata polearm can be shortened like a tachi via suriage and reshaped into a katana. Like a few other less known sugata shobu zukuri is usually found in tanto and wakizashi forms more often than katana and has evolved from styles normally used in naginata and nagamaki. By the way most early nagamaki are usually moroha zukuri or shobu zukuri so if you find a koto nagamaki naoshi sword with a yokote or in the unokubi zuki shape it was most probably made as a sword not as a polearm even if they are o suriage. There is a subtype of naginata called a nagamaki which can only be truly identified when it is with its koshirae.
Occasionally the early naginata blades are short that are often repolished and reshaped. Basically how the blade is mounted and used continue reading naginata and naginata naoshi. Most notable is the absense of a yokote border line between the tip and the cutting edge and a graceful curved slicing tip that was used to great effect against the mongol leather armor during their attempted invasions in the 13th century ad. The shobu zukuri geometry is quite different from your standard run of the mill katana with a blade that bears quite a few similarities to those korean swords the jingum.
The form is especially producted for the usage of large swing. I am not quite sure. Samuraiswords the nagamaki 長巻 is a unique sword design found only in japan with very few exceptions. Yet some features the tsuba having similar sizes with swords.
This would give it a shobu zukuri or unokubi zukuri style. The name itself means long wrapping and there is a very specific reason behind it that i m going to explain in this article. The name actually reflects on the wrap of the tsuka of this type of polearm.