The saya (sheath)
is normally hard wooden in order to carry the swords.It can be different color or different material ,high-grade saya is made of high quality hard wood and fully wrapped with genuine rayskin.
Saya is the Japanese term for a scabbard, and
specifically refers to the scabbard for a sword or knife.
Saya are normally manufactured from very lightweight wood, with a
coat of lacquer on the exterior. The wood is light enough that great
care must be taken when drawing the sword...