What is Koshirae

"Koshirae" refers to the external fittings of a katana sword used for carrying, including the scabbard (saya), hilt (tsuka), handguard (tsuba) etc. It's a collective term for the decorative parts of a Japanese sword, known as "sword fittings". Koshirae serves three main functions: protection of the katana blade, enhancement of practicality, and demonstration of the owner's dignity. There are many different style of Koshirae, they can be classified by the smiths and their era . This article will introduce the overview, history, and common types of Koshirae, these are valuable knowledge if you want to order a custom katana.

Koshirae

Koshirae refers to a series of external fittings for swords, including the hilt and scabbard for storing the blade, the tsuba, decorative fittings for wearing the sword, and various fittings for reinforcement. The production of Koshirae is thought to have started around the Yayoi period, and a variety of Koshirae designs have been invented in response to changes in the shape, use, and decoration techniques of swords up to the Edo period. The production of Koshirae is divided among artisans who specialize in making different parts such as scabbards and tsuba. Koshirae represents the high level of craftsmanship in each field.

Typical Koshirae
There are groups of Koshirae with common features according to time and region, and these are classified and referred to as "◯◯ Koshirae". Let's introduce four main ones.

Tensho Koshirae
Tensho Koshirae was created during the Warring States period and was a practical Koshirae used extensively on the battlefield. The hilt is shaped like a drum, with a constricted middle, often wrapped in rayskin (samegawa) and covered in leather. The scabbard is lacquered black, and the tsuba often lacks ornamental detail, giving it a simple and functional finish.

Momoyama Koshirae
Momoyama Koshirae was popular during the Azuchi-Momoyama period, and it is a luxurious and brilliant Koshirae that makes extensive use of gold for decoration. Using a technique called "Uchizame", where the bumps of rayskin are hammered onto a metal plate, gold plates are shaped like rayskin and overlaid on the front of the scabbard. You can also find ones where thin gold plates are wrapped around a red-lacquered scabbard.

Higo Koshirae
Higo Koshirae is said to reflect the aesthetic sensibility of Hosokawa Sansai, a lord of Higo domain and a tea practitioner who learned from Sen no Rikyu. The tsuba, menuki, and fuchigashira used are made by the artisans of Higo domain. It features austere decoration, combining the sensibility of the tea ceremony and the practicality of Iaijutsu, and it became popular in Edo around the end of the Edo period.

Satsuma Koshirae
Satsuma Koshirae is a type of Koshirae specialized for practicing the old style of swordsmanship called "Jigen-ryu", primarily in the Satsuma domain. To match the Jigen-ryu, which aims to defeat the opponent with a single strike upon drawing the sword, it has features such as a convex-shaped projection at the kaerizuno that allows the blade to be quickly drawn from the belt. The scabbard is often thicker, and the tsuba has a hole for a cord to prevent the hilt from slipping out

Tachi-Koshirae
As the shape and usage of swords changed over time, so did the Koshirae. From the Nara to Heian and Kamakura periods, swords, when mentioned, refer to the Tachi, which were worn hung from the waist with the blade facing downwards using an Obi (belt). However, during the Muromachi period, Uchigatana, which are inserted into the waist belt with the blade facing upwards, appeared. The Koshirae for Tachi is called "Tachi-Koshirae", and the Koshirae for Uchigatana is called "Uchigatana-Koshirae".

While there are universal fittings for the Tachi-Koshirae and the Uchigatana-Koshirae, the same parts may have different names, and there are also fittings unique to each. Let's start by looking at the Tachi-Koshirae.

Fittings of Tachi-Koshirae
The fittings unique to Tachi-Koshirae include the following:
Uto-gane
This is a metal fitting attached to protect the handle's tip, often featuring dense engravings. It's also referred to as "Helmet Metal".
Fuchi-kana-mono
This is a metal fitting attached to the mouth of the handle. Materials like gold, silver, copper, and brass are used, with relief carvings on the metal plate.
Ashi-kana-mono (First and Second Ashi)
These are metal fittings through which the Obidome, used to hang the Tachi, is passed. They are located just below the tsuba and a little further down, the one closer to the mouth of the sheath being called the first ashi, and the one further away, the second ashi.
Obidori
This is a decorative fitting or leather ornament for passing the Tachi cord through, associated with the Ashi-kana-mono.
Tachi-o
This is a braided or leather cord used to secure the sheath by wrapping it around the waist when wearing the Tachi. It's often a cord with a tortoiseshell pattern, about 3m in length, and when the sword is not worn, it is tied in a knot known as Tachi-musubi.
Seme-kana-mono
This is a ring-shaped metal fitting attached to the middle of the sheath to prevent it from splitting. A Kashiwaba-kana-mono, a fitting with a design resembling oak leaves, is often used.
Ishizuki-kana-mono
This is a fitting attached to protect the end of the sheath.

Uchigatana-Koshirae
The Uchigatana appeared in the Muromachi period, when combat styles shifted from horseback to foot, Uchigatana is lighter and easier to draw than Tachi. The primary difference is the way they are carried. Tachi are hung from the waist with the blade facing downwards, Uchigatana are carried inserted into the waist belt with the blade facing upwards. Let's take a look at the features of Uchigatana-Koshirae.

Fittings of Uchigatana-Koshirae
The fittings unique to Uchigatana-Koshirae include the following:
Kashira
This is a fitting attached to the end of the handle (Tsuka) to reinforce it. It often features the same design as the Fuchi.
Fuchi
This is a fitting attached to the mouth (near the Tsuba) of the handle to reinforce it. In most cases, the Fuchi features a matching design to the Kashira.

Kogai-bitsu, Kogai
Kogai-bitsu is a groove provided on the outer surface of the sheath to store the Kogai. The Kogai is a small tool used for grooming, such as fixing dishevelled hair.

Kozuka-bitsu, Kozuka
Kozuka-bitsu is a groove provided on the backside of the sheath for storing the Kozuka. The Kozuka refers to a small utility knife used for whittling wood or cutting paper. In the Edo period, the Kogai-bitsu, Kogai, Kozuka-bitsu, and Kozuka became more important for their artistic qualities as decorative pieces rather than their practicality.

Sageo
This is a cord used to secure the sword when it is inserted into the waist, by tying it around the waist to prevent the sword from slipping out. It is approximately 170 cm in length.
Kaeri-dzuno
This is a device hooked onto the belt to prevent the sheath from being drawn out together with the blade when drawing the sword.
Kojiri
This refers to the metal fitting attached to prevent the lower end of the sheath from breaking.

Universal parts for Tachi-Koshirae and Uchigatana-Koshirae
The parts universal to Tachi-Koshirae and Uchigatana-Koshirae include the following:
Tsuka (Handle)
The part of the sword used to hold the blade. Typically, it's made from the wood of the magnolia tree and covered with sharkskin.
Tsukamaki (Handle Wrapping)
A wrapping intended to reinforce the handle and improve its grip. This can be made from braided cord or leather thongs, starting from the edge and ending just below the pommel.
Mekugi (Peg)
This is a pin inserted from the front to the back of the handle to prevent the blade from slipping out. Originally it was the base of the Menuki, but it separated and became a functional Mekugi. They can be made from bamboo, buffalo horn, or metal.
Menuki (Ornament)
Originally a pin inserted from the front to the back of the handle to prevent the blade from slipping out, it later separated into two and was enhanced for decorative purposes. This fitting serves as a fulcrum and slip-stopper for the hand, and is installed near the middle of the handle on the front side, and closer to the pommel on the back side.
Tsuba (Guard)
A metal fitting attached between the handle and the blade. It serves to protect the hand holding the handle and to adjust the center of gravity of the sword.
Seppa (Washer)
A thin plate of metal attached to both sides of the Tsuba. It serves to firmly secure the Tsuba to the handle.
Saya (Scabbard)
The part of the sword where the blade is housed. Its role is to protect the blade from rain and dust, but from the early modern period onwards, it was often heavily decorated. While it's typically made of lacquered wood, there are also those covered with leather or wrapped in rayskin.

Koshirae is a big part of the aesthetic value of katana
Koshirae not only protect the blade but also enhance the practicality of the sword and demonstrate the dignity of the owner. They are works of art combining the skills of artisans in various fields, and no two are the same in the world. While it's common to focus on the blade when looking at Japanese swords, it can be said that the beauty of Japanese swords must includes the Koshirae.