Katana signed Bungo-no-kami Minamoto MASAYASU

Shinto early Edo period (kanbun era/circa 1661-) Owari
Length of cutting edge 64.2cm Curvature 1.5cm Width of Base 30.6mm Width of Yokote 20.4mm Thickness of base 6.8mm

NBTHK(Hozon) certificate

Blade construction: This is a brilliant katana of Shinogi-zukuri, Iori-mune. Mihaba width on base is a bit on wider side and Shinogi-ridge is high which has Shinogi-ji shaved off toward the back ridge holding massive volume of Hiraniku for durable cutting performance and solidly heavy on hand designed for martial advantages. There is harmonious ratio of curvature and suitable degree of tapering from base to point where upper Fukura area is swelling to a medium tip. This is the typical shape in circulation during Kanbun era (1661-) so called "Kanbun-shinto style". (click HERE for super sized image of entire blade)
Forging(Hada): Kitae is fine Ko-mokume. The entire skin of Hiraji shows sparkling martensite crystals of Ji-nie to generate precise darkish gleaming lines of Chikei activity.
Temper(Hamon): Hamon of visible hardening pattern starts with slanting Yakidashi on base and picturesque tall waistline slanting tassel-shaped Choji-midare . Hamon is a bit tight Nioi based and ravine of boundary line is covered with a bit on stronger side sparkling martensite crystal of Nie and the interior is filled in with mist-like Nioi. The entire hamon is flamboyantly active with sparkling Nie and misty Nioi.
Temper of tip(Boshi): Hamon of Boshi becomes calm straight of wavy Suguha then medium circle turns back a bit on longer side.
Tang(Nakago): UBU in original. Two mekugi-ana retaining holes. Takanoha V-shape filemarks. Shallow round shape bottom heel of Kurijiri. Back ridge has contoured round with greatly slanting left of Osujikai filemark. The inscription signature on Hakiomote starts with an official title of Bungo-no-kami 豊後守, name of clan Minamoto 源 and the name of smith MASAYASU 正全.

The smith MASAYASU 正全, real name Ishida Zen'zaemon 石田善左衛門 in Owari (now in Nagoya) was active during Kanbun to Enpo era (1661-) . He was descended from MASATOSHI 正利 of Sakakura-Seki school from Koto Muromachi period. After apprentice himself to the Mishiha school of an experienced master Igano-kami KINMICHI 伊賀守金道, he had set up his own studio at
Teppomachi town, Nagoya.
The subject katana features deep in Hamachi at the starting point of cutting edge on base that holds massive volume of Hiraniku, impressively brilliant blade among similar works from 17 th C in central Owari domain. Tango of Nakago remains good taste of patina from 350 years history that states V-shape filemarks and vibrant chiseled inscription is full of energy.
Silver Habaki collar, preserved in Shirasaya plain wood mounting.
Good polish/Condition scale: excellent (using a scale of mint-excellent-very good-good-fair-poor)
reference data : Iwata Ato, Owari-To-ko-fu, 1984