Katana in Shirasaya(NBTHK Hozon paper)
Signature : Mumei (Chiyozuru)
(We divide 4 sections for each sword as Saijyo saku, Jyojyo saku
Jyo saku and regular saki)This sword belongs to Jyojyo saku ranking.
The blade was polished.
Blade length : 68.1cm or 26.81 inches.
Sori : 1.8cm or 0.70 inches.
Mekugi : 4(1 filled up)
Width at the hamachi :3.18cm or 1.25 inches.
Width at the Kissaki :2.26cm or 0.88 inches.
Kasane : 0.67 cm or 0.26 inches.
Era : Nanbokucho period circa Bunwa 1352-1355
Shape: It is O-Suriage Mumei with Bo-Hi groove engraved
on both side in Kakinagashi style(The groove is engraved until the middle of nakago tang).
It is wide and thick solid shape. The Sori curvature is deep and kissaki is long end.
It is magnificent work.
Hamon: Nie Deki with soft gunome midare. Ashi is attached. Sunagashi activity is appearing.
Boshi is midarekomi(wavy) brush up hamon with kinsuji activities appearing.
Special feature :Chiyozuru is a sword smith of Rai school. He is said to by the son
of Rai Kuniyasu. He has moved to Echizen province and made swords
After he succeeded around Bunwa era(1352) 4 generation continues
until Bunan era of Muromachi period.
Hence, he is also highly rated as Chiyozuru or other name Echizenrai.
Because the name Chiyozuru has happy meanings, it is said that the sword
was sent as present between the Daimyos.
This work has much thickness and the jigane is good
with elegant feeling of that time remaining.
The human national treasure Honami Nisshu Sensei has attributed
this sword as Kashu Sanekage accordingly to the sayagaki.
Mumei sword is hard to distinguish as it could be either Chiyozuru or Kashu Sanekage.
The sword is not made later in any case.
Historical Background: Bunwa 2nd year, Kyogoku Hidetsuna
who was serving as the Samurai Dokoro no Tsukasa(a samurai office)
has been assasinated while under convey of Emperor Gokougon.
NBTHK Hozon paper
Aoi Art estimation paper : whole Oshigata.