"닌자 칼" refers to the traditional weapons used by 닌자, the covert agents of feudal 일본. These swords, often called "ninjato," are characterized by their straight blades and shorter lengths compared to typical samurai swords. They were designed for stealth and quick movements, making them ideal for surprise attacks and close combat. The design of the 닌자 칼 allowed for easy concealment, often carried in a scabbard on the back or hidden within clothing. While popularized in modern media, the historical accuracy of the ninjato's appearance and use is debated among scholars and enthusiasts of 무기 and 전통 무술.