What is Mumei in Japanese Katana terminology?

"Mumei" (無銘) refers to a sword that does not have an inscription, such as the name of the swordsmith, on the blade. There are swords that were originally made without an inscription (known as ""Ubu Mumei""). There are also swords that became ""Mumei"" as a result of a process called ""Osuriage"" (大磨上げ無銘). This process was carried out during the Warring States period when long swords made before the Nanboku-cho period were refashioned into shorter swords for better mobility. As a result of this process, the inscription was removed, making the sword ""Mumei"".

This term reflects the diverse circumstances and processes involved in sword making. The absence of an inscription on a sword can be due to the original design of the swordsmith or the result of refashioning the sword for practical reasons. The practice of refashioning long swords into shorter ones during the Warring States period underscores the changing needs and preferences of the samurai class during this period. Despite the absence of an inscription, these swords are still valued for their craftsmanship and historical significance."