What Is Nakago-jiri? 茎尻 — Tang-End Shapes for Kantei
The nakago-jiri (茎尻) is the shape given to the very end of a Japanese sword's tang (nakago) — the finished butt of the tang, cut and filed into one of several recognised forms such as kurijiri, ha-agari kurijiri, kiri or iriyamagata. Far from a random cut, this shape was a deliberate choice tied to a school, tradition and era, which makes the nakago-jiri a genuine clue in appraisal (kantei). Because the tang is never re-polished, the end shape usually survives intact and can be read directly.
For a collector, the nakago-jiri helps place a blade and helps flag alteration. A tang-end form that matches the claimed school and period supports authenticity, while a freshly cut, patina-free end on a supposedly old blade is a warning sign that the tang was shortened or reworked.
The main nakago-jiri shapes
Several standard tang-end forms recur across the tradition, each associated with particular schools and periods:
- Kurijiri (栗尻) — a rounded, chestnut-shaped end, symmetrically curved. This is the most common form and appears across many schools and eras, so on its own it is only a mild clue.
- Ha-agari kurijiri (刃上がり栗尻) — a rounded end that rises toward the edge side, so the curve is asymmetric with the edge corner higher. It is strongly associated with Bizen work and related traditions.
- Kiri (切り) — a flat, straight cut across the tang end, roughly perpendicular to the length. A blunt kiri end frequently signals that the tang was cut down during shortening (suriage).
- Iriyamagata (入山形) — a slanted, angular "mountain" shape, cut asymmetrically. It is a signature tang-end form of the Mino tradition and its offshoots.
- Kengyo (剣形) — a symmetrical pointed end resembling a shallow chevron, less common but distinctive where it appears.
How the nakago-jiri is read in kantei
An appraiser reads the tang-end shape together with the file marks (yasurime), tang taper, patina and any signature. On its own the nakago-jiri rarely proves attribution, but it narrows the field: an iriyamagata end pushes toward Mino, a ha-agari kurijiri toward Bizen, while a clean kurijiri keeps options open. The shape is weighed against the rest of the tang so that no single feature is trusted in isolation.
The original nakago-jiri also carries the tang's age directly. Genuine old ends show deep, even rust (sabi) and file marks worn soft by centuries, whereas a sharp, bright end betrays recent work. This is why the tang butt is scrutinised so closely on any blade claiming great age.
Shortening and the altered tang end
When a blade is shortened (suriage), steel is removed from the base of the tang and a new end is cut, usually as a plain kiri. This means many long, old blades that were cut down over the centuries now show a flat kiri end rather than their original shape. A kiri nakago-jiri with fresh-looking steel below deeply patinated tang above is a classic signature of shortening, often accompanied by a plugged or clipped mekugi-ana and a truncated signature.
Reading these signs together lets a collector distinguish an ubu (unaltered) tang, whose end shape and patina are consistent top to bottom, from a shortened one, where the end has been recut and the mei may be affected. That distinction feeds directly into how a blade is categorised and valued.
Why the nakago-jiri matters to a buyer
Because it is both a kantei clue and a condition indicator, the tang end deserves attention before purchase. A nakago-jiri whose shape, file marks and patina agree with the claimed maker and era supports the attribution; a mismatch — an "old Bizen" blade with a bright kiri end and modern-looking file work — is grounds to slow down and verify. Confirming these details, ideally alongside professional papers, protects both authenticity and value.
Frequently asked questions
What is the most common nakago-jiri shape?
Kurijiri (栗尻), the rounded chestnut-shaped end, is the most common tang-end form and appears across many schools and periods. Because it is so widespread, it is only a mild attribution clue on its own and is read together with other features.
Does the tang-end shape really help identify a school?
Yes, in combination with other evidence. An iriyamagata end leans toward the Mino tradition and a ha-agari kurijiri toward Bizen, but appraisers weigh the nakago-jiri alongside file marks, patina, tang shape and any signature rather than trusting it alone.
Why do many old swords have a flat kiri tang end?
A flat kiri end often results from shortening (suriage), where the base of the tang is cut off and a new plain end is made. Many long koto blades were shortened over the centuries, leaving a kiri end that replaced the original shape.
How does the nakago-jiri reveal a fake or altered blade?
The original tang end shows deep, even patina and softened file marks consistent with the blade's claimed age. A bright, sharp-edged end, or a shape that contradicts the stated school and era, suggests the tang was recut, aged, or otherwise altered.