Katana in Shirasaya, with Koshirae(NBTHK Tokubetsu Kicho paper)
Koshirae (mounting) NBTHK Tokubetsu Kicyo Token To-so-gu.
Signature :Mumei(unsigned) attributed as Bishu Osahune Sukesada.
(We divide 4 sections for each sword as Saijyo saku, Jyojyo saku
Jyo saku and regular saku)
ThisMumei(unsigned) attributed as Bisyu Osahune Sukesada belongs toFutu saku(regular ) ranking.
The blade was polished
Habaki :Gold foiled and syakudo dounle habaki.
Blade length : 64.5cm or 25.4inches.
Sori : 2.3 cm or 0.90inches.
Mekugi : 1
Width at the hamachi : 2.63cm or 1.04inches.
Width at the Kissaki : 2.33 cm or 0.92inches.
Kasane : 0.65cm or 0.26inches.
Era : Late Edp period. Tenbun era(1532)
Shape : The blade is small suriage mumei(unsigned) the blade is regular size with
and thickness deep sori and longer kissaki nice elegant shape.
Jitetsu :Itame hada and mokume hada mixed with jinie attach and some lose hada
openings but not so bad.
On the Ji, Uturi is appearing.
Hamon : Niedeki Choji midare with small ashi, and yo work.
Boshi is midarekomi style.
Special feature : At war time late Muromachi, it was necessary to make many swords for demanding the consumers.
So we can say 3 sections for these swords by the quality.
First is demanding high raking like Daimyo class sword which is called Zokumyo uchi sword, next is Bizen Kuni Osafune and third is Bishu mei(signature) which is called Kazuuchi mono mass productive items.
I think this sword looks Kazuuchimono style sword but the blade has passed more than 490 years.
Koshirae : Handachi Kosirae: good condition.
Tsuba :On the round syakudo, Hukurin(cover) is covered with gold color.
clouds and a dragon are engraved with gold color.
Fuchikashira :Kojiri: Shakudo plate.
Saya : brown red Issimeji saya.
Menuki : shishi dogs are mede by shakudo plate: Ko-Mino or Ko-goto nice items.
Historical background: August 25th 1543, Portuguese casted ashore Tanegashima island which is located southern part of island and Portuguese presented matchlock.
And after 10 yeas or so Many Hinawajyu(matchlock) were made in Japan and changed the battling way by using modern matchlock instead of Swords.
NBTHK Tokubetsu Kicho paper
Aoi Art estimation paper : whole Oshigata.