The sheath or scabbard of a samurai sword is called a saya in Japanese. The saya is an integral part of the sword and serves to protect and store the blade when it is not in use. It is typically made from wood and is designed to fit the specific sword it accompanies.

The saya is crafted with precision and attention to detail. It is often lacquered to provide a smooth and durable finish, as well as to protect the wood from moisture and damage. The saya is usually fitted with other components, such as a kurikata (knob for attaching the sageo or cord), a koiguchi (mouthpiece), and a kurikata-hitsu (knob for attaching accessories). These elements aid in securing the sword and facilitate easy drawing and sheathing.

The saya can also be decorated to reflect the aesthetic preferences of the owner or the traditions of a particular school of swordmaking. It may feature ornate metalwork, hand-painted designs, or other embellishments.

In summary, the saya is the sheath or scabbard of a samurai sword, designed to protect, store, and facilitate the drawing and sheathing of the blade. It is an essential component of the overall sword and plays a significant role in both the functionality and visual presentation of the weapon.