Photographs
Photographs by the seller at origin.
The piece
A sturdy blade of about 1658 by a smith to the Katō house of Aizu, with an ubu tang and a koshirae combining a solid silver tsuba with a black ishime saya.
Masanaga was a smith to the house of Katō Yoshiaki, lords of Aizu at 400,000 koku, and comes from a well-documented line: his grandfather Nagakuni studied under Harima no Kami Terahiro, a pupil of Umetada Myōju, while his father entered Myōju's school directly, making him a fellow student of the first Tadayoshi of Hizen. The blade, signed 陸奥会津住正長 (Mutsu Aizu-jū Masanaga), dates from about 1658 and shows the Kanbun-era outline: 71.2 cm nagasa, 1.0 cm sori, 3.08 cm motohaba and 1,007 g without the saya. The hada is a vigorous ko-itame and the hamon a gunome-midare in nioi with ko-nie. The original seller points to its closeness to the work of Aizu Michinaga, rated saijō ō-wazamono. The photographs show the tang ubu on both faces, with a single mekugi-ana, a clean kurijiri and a well-spaced signature. NBTHK Tokubetsu Hozon papers dated 16 February 2026; the Japanese registration was reissued in 2025 after the previous one was lost. The koshirae carries a solid silver tsuba (gin-muku) and a black ishime-ji saya with inrō-kizami carving, a navy sageo and a tsuka of dark ito over same. No shirasaya is included.
Strong points
- NBTHK Tokubetsu Hozon (16 February 2026), with koshirae
- Ubu tang with a single mekugi-ana, confirmed by the photographs
- Solid silver tsuba (gin-muku) and inrō-kizami saya in black ishime
- 1,007 g without the saya: a robust cross-section
- Lineage tied to the Umetada Myōju school through the smith's father
Points to bear in mind
- The original seller declares light rust in several places from the passage of time
- No shirasaya included
- The signature carries no date
- In the photographs the tsuba looks blackish, consistent with patinated silver, though the original listing does not say so
Score
125 pointscurrent max. 255
-
Certificate
+50
NBTHK Tokubetsu Hozon paper +50
-
Tang
+20
Tang intact according to the photographs +20
-
Declared condition
−50
The original seller declares flaws 0 · light red rust −50
-
Signature and date
+15
Signed, with no engraved date +15
-
Mounting
+50
Mounting from the same period as the blade +50
-
Blade
+10
71.2 cm: within the usable range +10
-
Shirasaya
0
No shirasaya: one will have to be made 0
-
Price
+30
Price: the more affordable, the more points +30
The score adds and subtracts points for each feature of the piece and has no ceiling: the highest in the catalogue today is 255. It is computed from the record, not from an opinion. The mounting starts from what is known of its period, adds what vouches for it (its own NBTHK paper, a signed fitting, a crest) and subtracts what has been restored (saya, ito, same, habaki or sageo).
Measurements
- Nagasa
- 71.2 cm
- Sori
- 1 cm
- Tang
- Intact according to the photographs
- Certificate
- NBTHK Tokubetsu Hozon
- Mounting
- Period mounting
- Storage shirasaya
- No
- Smith
- Ōshū Masanaga
- Period
- Shintō (1596-1780)
- Dating
- Kanbun era (c. 1658)
- Province
- Mutsu (Aizu)
- Mekugi-ana
- 1
- Paper date
- 16 February 2026
- Condition
- Serious flaw declared
- Signed
- Yes
- With an engraved date
- No
- Motohaba
- 3.08cm
- Motokasane
- 0.65cm
- Sakihaba
- 1.98cm
- Sakikasane
- 0.39cm
- Blade weight
- 1007gr
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