A Shirasaya katana is a style of Japanese sword that is characterized by its plain wooden scabbard (saya) and handle (tsuka). The term "Shirasaya" translates to "white scabbard" in Japanese, referring to the simple, unadorned appearance of the saya.

The Shirasaya style was historically used for storing and preserving the katana blade when it was not in use. The wooden scabbard provides protection for the blade while allowing it to breathe and preventing moisture buildup. The lack of decorative fittings on the saya and tsuka distinguishes the Shirasaya from other more ornate and decorative sword styles.

The Shirasaya katana is often seen as a minimalist design, focusing on the natural beauty of the sword blade itself. The plain wooden scabbard and handle allow for a clear view of the blade, highlighting the craftsmanship and the unique hamon (temper line) of the sword.

In contemporary times, Shirasaya katana are sometimes sought after by collectors and enthusiasts due to their simplicity, elegance, and focus on the blade. However, it's worth noting that the Shirasaya style is not typically used for practical combat purposes, as the lack of a guard (tsuba) and other fittings makes it less suitable for actual swordsmanship.