AS25316 Katana in Shirasaya with Koshirae (NBTHK Tokubetsu Hozon Token) (Consignment Sale) Signature: Nagasone Okisato Nyudo Kotetsu

Ordering Number: AS25316

Katana in Shirasaya with Koshirae (NBTHK Tokubetsu Hozon Token) (Consignment Sale)

Signature: Nagasone Okisato Nyudo Kotetsu
長曽祢興里入道乕徹

Shinto; Saijo O Wazamono; Saijyo Saku; Musashi
We divide 4 sections for each sword as Saijyo Saku, Jyojyo Saku, Jyo Saku and Regular Saku.
This work is ranked as Saijyo Saku for Nagasone Okisato Nyudo Kotetsu.
Habaki: Silver foiled single Habaki and gold foiled single Habaki
Blade Length: 70.0 cm (27.56 in)
Curvature: 1.2 cm (0.47 in)
Mekugi Hole: 1
Width at Base (Motohaba): 2.94 cm (1.16 in)
Width at Tip (Sakihaba): 2.05 cm (0.81 in)
Thickness of rim (Kasane): 0.64 cm (0.25 in)
Sword Weight: 700 g
Era: Around Kanbun era, Edo period (circa late 1600s)
Shape: Slightly wide blade with thick kasane, appropriate curvature, and an extended kissaki forming a well-balanced appearance.
Jigane: Finely forged with vivid chikei and a relatively clear utsuri. The shinogi-ji and hira-ji are nearly unified. Although most Shinto jigane show masame in the shinogi-ji, here it is itame throughout, forming a remarkable one-piece appearance.
Hamon: A bright and clear suguha hamon with occasional small ashi. The boshi is curved and rounded with visible kinsuji.

Features:This is a katana by Nagasone Kotetsu, who is rated as Saijyo Saku and also classified as a Saijyo Oowazamono (supreme sharpness). Nagasone Kotetsu was originally an armor maker from Echizen and is said to have moved to Edo around 1656, at the age of 50, where he transitioned to becoming a swordsmith and adopted the name Sannojō.

He initially used the name Okisato, and upon becoming a monk, began inscribing his blades with the characters for “old iron” (Kokutetsu), later changing to “Kotetsu,” and from August 1664, he used the characters “乕徹” for Kotetsu.

His earliest dated works begin in 1656, and the latest are from 1677.

The signature of Kotetsu is fine and sharply carved, and this piece shows those characteristics well.
Kotetsu, a swordsmith loved by many, rarely appears on the market, making this a special opportunity. The seller has now decided to release it, allowing us to present it.

Koshirae: (Two tsuba included)
Tsuba 1: Silver base with high-relief carving of wave design, signed “Hakuodo Jujui”
Tsuba 2: Mokko-shaped shakudo nanako base. The rim is covered with gold.
Fuchikashira: Silver with high-relief carving of waves, partially detailed in gold
Saya: Glossy black lacquer saya with 11 plovers flying on both sides in a charming landscape
Menuki: Solid gold with high-relief carving of shishi (lion) motif
Kojiri: Silver with high-relief wave design
Kurikata: High-relief carving of wave design

Aoi Art’s Comment: This is a work by Nagasone Okisato Nyudo Kotetsu, paired with a remarkable koshirae.
The saya, decorated with silver waves and flying plovers, represents a masterpiece-grade mount from the Meiji to Taisho era, when highly skilled craftsmen were still active.
Originally an armorer from Echizen (modern-day Fukui), Kotetsu moved to Edo around age 50 and likely studied under many swordsmiths, becoming a renowned master.
As such, there may be various influences present in his swords. This particular piece shows vivid utsuri and unique jigane where the shinogi-ji and hira-ji share the same itame pattern, differing from most typical works.
It is said that Kondō Isami once owned a Kotetsu or that Kotetsu used an alias, though the truth is unclear. Nonetheless, Kotetsu remains a legendary swordsmith.
The koshirae is an exceptional piece. We highly recommend this outstanding sword and mount.

NBTHK Tokubetsu Hozon Token
Aoi Art estimation paper with whole oshigata