What is Nakazori in Japanese Katana terminology?

"Nakazori" (中反り) refers to a type of curvature in a sword where the center of the curve is approximately in the middle of the blade. This style is often seen in the works of the Yamashiro tradition, which was based in Kyoto, hence it is also referred to as ""Kyozori"" (京反り). This style became popular around the middle of the Kamakura period.

This style of sword construction reflects the aesthetic sensibilities and practical considerations of the swordsmiths of the Yamashiro tradition. The curvature in the middle of the blade would have made the sword more balanced and easier to handle. The fact that this style is often seen in the works of the Yamashiro tradition underscores the influence of regional styles in sword making. The popularity of this style during the Kamakura period reflects the evolving needs and preferences of the samurai class during this period."