This is an outstanding katana by the well known Chikuzen smith, Nobukuni Yoshikane. He was called Sukezaemon and was the son of Nobukuni Yoshitsugu. He was later the father of Nobukuni Shigekane.
He worked in Chikuzen province around the Kanbun and Tenwa eras (1661-1681). He passed away on August 22, 1693 (Genroku Rokunen Hachigatsu Nijûninichi). Yoshikane is rated as a Jo-saku maker by Fujishiro and is given 35 points by Hawley.
This katana is wonderful example of his of work. It has a nagasa of 28 inches or 71.1 cm, a moto-haba of 1.23 inches or 3.12 cm, and a saki-haha of 0.90 inches or 2.3 cm. The kasane is 0.28 inches or 0.7 cm. It has a typical Kanbun-Tenwa shinto sugata with a stout shape, thick kasane and a shallow sori. It also has a relatively large chu-kissaki.
The jihada is a very tight mokume hada with masame hada in the shinogi-ji. The grain can be easily seen within the hamon creating a striking appearance. The hamon is a gunome-midare sunagashi majiri as is typical of this smith. The hamon is very wide, reaching the shinogi-ji at various points along the nagasa. The sunagashi majiri (mixed in) is especially strong in this blade adding great beauty to the overall appearance of the hamon. The habuchi is nioi deki covered by ko-nie.
The bôshi is midare-komi and fills almost the entire kissaki. The sunagashi majiri continues into the boshi, especially on the omote side of the bôshi. There is a ko-maru near the top with a short kaeri.
The nakago is ubu and the blade is signed Chikuzen Jû Minamoto Nobukuni Yoshikane (筑前住源信国吉兼). It is not dated. This blade comes with NBTHK Hozon Tôken papers dated in 2003. I just purchased this sword in Japan where it is common to only get Hozon papers to verify the authenticity of the signature and not to submit a sword for the higher Tokubetsu Hozon papers because of the added expense. I see no reason that this sword should not be awarded Tokubetsu Hozon papers if submitted for such.
Accompanying this sword is a fine set of Higo koshirae. The fuchi and kashira are iron that is profusely covered in a silver inlay in the form of flowers and tendrils. The menuki are shakudo and appear to be some form of geometric design. The tsuba is iron with a shakudo rim. It is probably of the Owari school. The saya is beautifully lacquered in a reddish lacquer with black undertones. There are several designs of chrysanthemums and paulownia flowers in black lacquer decorating the saya. The kojiri is also of iron and has the design of a dragon inlaid in silver. The tsuka is covered with doe skin ito as is very popular with Higo koshiare. This koshirae is in excellent condition and shows good age.