On a katana, the "Kashira" refers to the pommel or butt cap located at the end of the handle (Tsuka). The Kashira is typically made of metal and serves both functional and decorative purposes.

The Kashira is an essential component of the katana's handle, providing balance and stability to the overall sword. It helps counterbalance the weight of the blade and contributes to the overall feel and handling of the weapon. The Kashira also serves to secure the Tsuka's wrapping material (Tsuka-ito) in place, preventing it from unraveling or slipping.

In terms of design, the Kashira can vary widely and may feature intricate engravings, decorative motifs, or the use of precious materials. It often complements the other fittings on the katana, such as the Tsuba (guard) and Fuchi (collar), in terms of style, theme, or material.

The Kashira, along with other fittings like the Tsuba, Menuki, and Fuchi, adds aesthetic value and personalization to the katana, reflecting the owner's taste or the craftsmanship of the swordsmith.

While the Kashira primarily serves functional and decorative purposes, it also plays a role in the overall balance, integrity, and aesthetics of a well-crafted katana.