The Koshirae is the mounting 'worn' by the Japanese sword (e.g. Katana), when it is being worn by its owner, whereas shirasaya is the wooden sheath and grip the sword wears when in storage. Katana of the 16th or 17th Century, with its saya. ...

Picture shows an Edo-era Higo style Koshirae in the proper manner a Koshirae should be presented with the tsuka to the left. Image File history File links A picture of a edo era Koshirae. ...

Origin of the word The word Koshirae is derived from the verb "koshirareru", which is no longer in use nowadays. Usually "tsukuru" is used instead; both mean "make, create, manufacture". More accurate is actually "Toso", which means sword-furniture: "Tosogu" are the parts of the mounting in general, and "Kanagu" stands for those made of metal. "Gaiso" are the "outer" mountings, as opposed to "Toshin", the "body" of the sword.

Source: Koshirae: Nihon Token Gaiso - The Mountings of Japanese Swords, by C. U. Guido Schiller.

The individual parts of the koshirae

Kashira - butt cap on the end of the hilt

Fuchi - pommel (above the guard/tsuba)

Same-kawa - ray skin wrapping of the handle

Menuki - ornaments on the hilt (under the silk ito) initially used to prevent hand slipping during combat

Tsuba - sword guard

Tsuka - hilt

Tsuka-maki - silk wrapping on the hilt a.k.a "ito"

Habaki - metal collar used to prevent the sword from touching the inside of the scabbard

Seppa - washers above and below the tsuba of a samurai sword

Kozuka - small utility knife and handle usually located in a 'pocket' on the scabbard

Kougai - spike carried sometimes as part of Katana-Koshirae in another 'pocket'

Kuri-kata - ring on the side of the scabbard for attaching Sageo

Sageo - cord used to tie scabbard to the belt/obi when worn

Further readings Koshirae: Nihon Token Gaiso - The Mountings of Japanese Swords