What is Katana-bukuro in Japanese Katana terminology?

"刀袋" or "Katana-bukuro" translates to "Sword Bag" in English. It is a bag used to wrap and protect the scabbard (Saya) and the hilt (Tsuka) of a sword from sun exposure and friction. The bag also serves to prevent the blade from accidentally slipping out by securing the scabbard and hilt with a cloth. The sword bag for a plain wooden scabbard (Shirasaya) is relatively simple, but the bag for a decorated scabbard (Koshirae) often uses a more ornate material for the cloth and includes a tassel on the cord.