What is Takenoko-zori in Japanese Katana terminology?

"Takenoko-zori" (筍反り) refers to a type of inward curvature often seen in short swords. The term ""Takenoko-zori"" is derived from the resemblance of the blade's shape to that of a bamboo shoot (""Takenoko"" in Japanese), with the tip of the blade (Kissaki) slightly leaning towards the edge. This style is often seen in works from the Kamakura period. It should be noted that some swords have taken on this shape as a result of being polished over many years.

This style of sword construction reflects the practical considerations and aesthetic sensibilities of Japanese swordsmiths during the Kamakura period. The inward curvature of the blade would have made the sword more effective for thrusting, while the resemblance to a bamboo shoot adds a touch of natural beauty. The fact that some swords have taken on this shape as a result of being polished over many years underscores the impact of maintenance practices on the sword's appearance."