Naginata-Naoshi: The Art of Converting Naginata Polearms into Swords During the Muromachi and Edo Periods
* Image is for illustrative purposes only.Table of Contents
What is Naginata-Naoshi? —— The Mystery of Weapon Repurposing in Japanese Sword History
"Naginata-naoshi" refers to swords created by cutting off the handle portion from a naginata blade, creating a new nakago, and reconstructing the blade as a katana, wakizashi, or tanto. While it is a form of "suriage" (shortening), it is more fundamentally a transformation than merely adjusting length, as it involves converting a hafted weapon into a Japanese sword worn at the waist.
Naginata-naoshi blades retain distinctive characteristics of their original naginata forms and possess a unique appearance distinctly different from ordinary katana.
From Naginata to Katana —— Why Were They Reconstructed?
The Decline of the Naginata and Rise of the Katana in the Muromachi Period
The naginata was a primary weapon in battles from the Heian and Kamakura periods through the Northern and Southern Courts and early Muromachi period. Specialized in striking down mounted warriors from below, the naginata held significant presence on the battlefield.
However, from the mid-Muromachi period onward, combat styles changed. After the Onin War (1467), urban warfare and infantry-focused combat made the poor maneuverability of the long-hafted naginata apparent, and the katana (Japanese sword worn at the waist) emerged as the primary weapon.
Within this transition, demand arose for reconstructing existing naginata into katana. It would be wasteful to discard a high-quality naginata blade as material. By removing the handle and reconstructing it as a blade, the naginata found a second life.
Samurai Women and Naginata-Naoshi in the Edo Period
In the Edo period, naginata-naoshi acquired another context. In Edo samurai society, the notion that "the naginata is a woman's weapon" became established, and it was customary for samurai women to study naginata technique.
However, in an era of peace without opportunity for actual combat, naginata-naoshi wakizashi and tanto reconstructed in forms that could serve as formal dress accoutrements were prized as protective implements and wedding furnishings for women. Wakizashi derived from naginata carried added value as "high-quality blades made from naginata," functioning as furnishings that displayed the status of samurai women.
Naginata-Naoshi Blade Shape —— Differences from Ordinary Katana
Naginata-naoshi blades retain the shape characteristics of their original naginata and possess a unique appearance distinct from ordinary katana. The main differences are as follows.
| Feature | Ordinary Katana | Naginata-Naoshi |
|---|---|---|
| Tip width/base width ratio (taper ratio) | Approximately 0.55–0.65 | Can be 0.4–0.5 or less |
| Position of curvature | Typically waist curvature or mid-curvature | Often retains a tip curvature tendency |
Ratio of Base Width to Tip Width (Fumibari)
The basic form of a naginata blade is that the blade width increases sharply from the edge toward the handle. This is called "fumibari of the naginata." Blades reconstructed as naginata-naoshi retain traces of this fumibari and often possess a "steep taper" where the tip width is extremely narrow compared to the base width.
While the typical katana has a tip width/base width ratio (taper ratio) of approximately 0.55–0.65, naginata-naoshi can be 0.4–0.5 or less.
Position of Curvature
The naginata's characteristic curvature is "kissaki-zori," concentrated toward the tip (blade side). Blades reconstructed as naginata-naoshi often inherit this tip-curvature tendency.
In contrast, ordinary katana typically feature waist curvature (base side) or mid-curvature, so when experts see a blade with tip curvature, they judge it to be "possibly a naginata-naoshi."
Thickness and Cross-sectional Shape
Because naginata blades were designed to prioritize cutting power, they tend to have "thinner thickness (kasane) and wider edges" than ordinary katana. Naginata-naoshi blades often retain this thin, wide cross-sectional shape.
Shape of the Nakago
The most certain evidence of naginata-naoshi is the nakago. Because the original naginata's nakago is remade (or shortened) for naginata-naoshi, the condition of the nakago's rust, file marks, and mekugi holes can give the impression of "being made afterward." Sometimes the mei inscription also notes that it is a naginata-naoshi.
Famous Existing Naginata-Naoshi Examples
Some notable examples of naginata-naoshi in Japanese sword history follow.
Wakizashi "Kotegiri Gou" "Gou" is attributed to Gou Yoshihiro of Etchū, one of the Masamune Ten Masters, and survives as a naginata-naoshi. Gou's blades frequently include naginata-naoshi, and are known among sword enthusiasts as "naginata-naoshi Gou." The "Kotegiri Gou" said to have been owned by Toyotomi Hideyoshi is a prime example.
Naginata-Naoshi by Master Smiths of Various Periods Blades by renowned smiths of the Kamakura and Northern and Southern Courts periods (Osafune-school and Masamune-school) include naginata-naoshi, and their value is recognized by certification documents noting "naginata-naoshi." Older naginata-naoshi tend to increase in value as the quality of the original naginata increases.
Key Points for Identifying "Naginata-Naoshi" in Certification
Accurate identification of naginata-naoshi requires the following observations.
- Taper ratio confirmation — Measure the base width and tip width; if the tip width/base width ratio is 0.5 or less, suspect naginata-naoshi.
- Position of curvature — If tip curvature is pronounced, naginata origin is likely.
- Position of yokote and shape of kissaki — Kissaki of naginata-naoshi are often recut as "inobushi-gata" or "ko-kissaki." Those retaining the original naginata's kissaki shape (also called "nama-kissaki") are especially rare and valuable.
- Condition of the nakago — Confirm the number and position of mekugi holes and condition of rust. Naginata-naoshi often have relatively short nakago.
Conclusion —— Blades That Lived On Through Change
Naginata-naoshi reconstruction is emblematic of how Japanese swords changed form in response to the demands of each era and continued to assume new roles. The story of a single blade's transformation—"running through the battlefield as a naginata, finding its place at a samurai's waist as a katana, and taking vows at a wedding ceremony as a wakizashi"—offers us a perspective that views the Japanese sword not merely as a weapon but as a witness to culture.
When appreciating a naginata-naoshi blade, please sense within its unique taper and tip curvature the memory of the naginata that once raced across the battlefield.
