What is Saijo O-Wazamono in Japanese Katana terminology?

"""Saijo O-Wazamono"" (最上大業物) refers to the highest ranking of Japanese swords in terms of sharpness. The term ""Saijo O-Wazamono"" is derived from the works ""Kaiho Kenjaku"" (懐宝剣尺) and ""Kokon Kaji Bikou"" (古今鍛冶備考) by the professional sword testers Yamada Asaemon Yoshimutsu (山田浅右衛門吉睦) and Sudo Godayu Mutsuzumi (須藤五太夫睦済). They divided the results of their sword testing into four grades, with ""Saijo O-Wazamono"" indicating the top grade.

This classification system reflects the importance placed on the sharpness of a sword in samurai culture. A sword's sharpness was not only a measure of its quality but also a matter of life and death for the samurai who wielded it. The fact that these swords were tested and ranked underscores the high level of craftsmanship and the rigorous standards of quality in Japanese sword making. The ""Saijo O-Wazamono"" swords, as the highest ranking, represent the pinnacle of this tradition."