What is Oosuriagemumei in Japanese Katana terminology?

"Oosuriagemumei" (大磨上げ無銘) refers to a Japanese sword that has been significantly shortened by a process called ""Oosuriage"" (大磨上げ). In this process, the tang (Nakagojiri) of the sword is significantly trimmed down to the point where all inscriptions, including the signature (Mei) and file marks (Yasurime), are completely removed, resulting in an unsigned sword.

This process is typically undertaken when a sword is damaged or broken, or when it needs to be adjusted to fit a new owner. The end result is a shorter sword with no remaining inscriptions, hence the term ""Oosuriagemumei"" which translates to ""greatly shortened and unsigned"".

While this process can result in the loss of valuable historical information, it also allows for the continued use and preservation of the sword. It is a testament to the practicality and adaptability of Japanese swordsmanship, where the functionality of the sword is prioritized over preserving its original form."