The Tate-maru gata oval shape, Yamagane bronze ground Tsuba - six Mitsudomoe crests engraved on both sides, and the polished rim is similarly sharply engraved. The thickness increases gradually from the middle lower Seppa-dai to the rim, and the jet-black Nanako pattern applied vertically and horizontally shows the eternal wear of over 500 years.

The term "Kokin-ko" refers to metalworkers from before the Muromachi period who did not leave signatures on their works

Muromachi period