What is Kuchikanamono in Japanese Katana terminology?

The term "Kuchikanamono" (口金物, くちかなもの) refers to a metal fitting used to reinforce the opening of the scabbard (Saya) of a Japanese sword. Its name is derived from its resemblance to the mouth of a carp (Koi in Japanese). This fitting is one of the components that come with a decorative sword (Shitachi), and it is made of metal. In the case of a long sword (Uchigatana), it is referred to as "Koiguchi". This terminology is used to describe the specific characteristics of the sword's structure, contributing to its overall aesthetic and functional design.