National Treasures & Important Cultural Properties
of National Institutes for Cultural Heritage, Japan

　The Aoe school emerged in Bichu no Kuni during the Kamakura period and the existing swords of the school can be traced back to the Northern and Southern Courts period. The swords of the Aoe school made in the late Kamakura period are called Chu-Aoe and this is a Chu-Aoe sword made by Yoshitsugu. Many Chu-Aoe swords bear the inscription of the creation year, place or the title of a government post like this one. Their jigane (the ground metal) shows a small wood grain pattern and some have a sumihada (a black transparent spot pattern). While their hamon (the blade pattern) is mostly in the suguha (straight) style, some have a narrow nioiguchi (the dividing line between the hamon and the ground) and others have a brilliant sakachojiba (a slanted clove pattern).
　The ground metal of this tachi (a sword made to be worn with the cutting edge down) demonstrates chirimenhada (a crepe-like pattern), which is a small itamehada (a wood grain pattern), unique to the Aoe school with utsuri (a white misty formation that runs parallel to the hamon in the ground metal) across the blade and partial danutsuri (literally a tier reflection). The hamon (the blade pattern) features kochojiba (a small clove pattern) with little height difference and a narrow nioiguchi. This sword was presented to Emperor Meiji by the Mori family in the Meiji period.