While popular depictions often associate ninjas with the use of katana, historically, ninjas (also known as shinobi) did not primarily use katana as their main weapon. The katana was the preferred weapon of samurai warriors and was associated with the warrior class in feudal Japan.

Ninjas were covert operatives and spies who relied on stealth, deception, and unconventional tactics. Their weapons of choice were typically more practical and suited to their specialized missions, which often involved infiltration, intelligence gathering, sabotage, and guerrilla warfare. Some of the weapons commonly associated with ninjas include:

1. Ninjato: Also known as a ninja sword, the ninjato is a straight-bladed sword often depicted as shorter than a traditional katana. It was believed to be a specialized weapon used by ninjas, although historical evidence for its exclusive use by ninjas is scarce.
2. Shuriken: Shuriken, commonly known as throwing stars or ninja stars, were small, handheld weapons used for throwing. They were designed to distract, disable, or inflict non-lethal injuries to targets.
3. Kusarigama: A kusarigama is a weapon that combines a sickle (kama) with a chain (kusari). It allowed for both melee strikes and ranged attacks, offering versatility and surprise in combat.
4. Fukiya: Fukiya, or blowguns, were used by ninjas for long-range silent attacks. They were capable of launching small poisoned darts or projectiles to incapacitate enemies.
5. Kama: Kama were sickles used primarily for agricultural purposes, but they could be adapted as weapons by ninjas. They were useful for close-quarters combat and had versatile applications.

Ninjas were skilled in multiple weapons and tools, adapting their arsenal to fit their specific missions and circumstances. While the katana is often associated with ninjas in popular culture, it was not their primary weapon of choice.