What makes a ninjato different from a katana in blade shape?
Updated Feb 2026
The most visible distinction is the blade geometry. A katana features a pronounced curvature, called sori, that typically measures between 1 and 2 centimeters along the spine. A ninjato has a straight or nearly straight blade with minimal to zero sori, giving it a distinctly angular profile. This straight design also means the kissaki (tip) is shaped differently — often a simpler, more acute point rather than the curved yokote line seen on katana. For collectors, the straight silhouette offers a striking contrast when displayed alongside curved Japanese swords, making the ninjato a strong visual complement in a mixed collection.