The Kama like many of the other Okinawan weapons, started as a simple farm implement — the sickle or mini scythe.

This explains the similarity to the Grim Reaper’s weapon, the scythe which is simply a long-handled, longer-bladed version of the kama. The shorter kama version was used to cut and gather rice, wheat, grass, and other crops. The handy tool was used not only in Okinawa but also in many other places throughout Southeast Asia. In fact, the kama makes its appearance in many other martial arts in the Philippines, Malaysia, Indonesia, and even China.

As is a common story among Okinawan weapons, the Japanese kama became a weapon when the ruling Samurai class banned and confiscated weapons from the peasants. When you had nothing else to defend yourself with, the wicked blade on this scythe and kama made a handy substitute. These tools didn’t even have to undergo much evolution to be used as weapons.

Though small and relatively easy to conceal, the kama is an effective weapon. They are typically used in pairs with one in each hand. The Okinawan peasants loved them because they were effective at defending against long-range weapons such as the bo staff or samurai sword.

The kama were used to trap the opponent’s weapon and disarm them. Some kama having a little notch where the blade meets the handle for this very purpose. The blade itself did serious cutting damage. The point of the blade was used for hooking or stabbing in a circular motion. In combat both the point and sharpened edge of the metal blade were called into use. The hard edge of the blade would be kept razor-sharp thus inflicting serious damage. Common moves include blocking or deflecting an attack with one kama and mounting an immediate, almost simultaneous, counterattack with the other.  

Another version of the kama is the Kusarigama or "Chain-sickle."  This was a true traditional Japanese weapon that consists of a kama attached to a metal chain with a heavy iron weight at the end. The kama was held in the left hand while the the chain was swung in the right hand and hurled at the enemy's face, arms or legs to strike with the weight. The chain was used to entangle the enemy's wrist or leg while containing the movements of the enemy and then slashing the enemy with a blade of kama.

The Kusarigama was a good weapon that was used in various ways by skilled users. Since the kusakarigama offered little in the way of defensive capabilities, if the opponent dodged the first blow and countered, the wielder was likely to have great difficulty dealing with the opponent as it required time to regather the weighted chain. Thus, the kusarigama was and still is a difficult weapon to master, requiring intensive training.

The practical use of the kama is taught only a few martial arts schools today, with many teaching only kata for competitions. Most competitors often simply adapt their own empty hand routines while holding kama with little actual knowledge of how the weapon is used in real combat. The techniques in competition employ elaborate weapon-juggling routines, throws, tosses and other tricks that differ radically from its true intended use.