The kama was the traditional sickle of Japanese peasants. Consisting of a short wooden handle (about 13 inches is typical) to which a gently curved 7-inch blade is affixed at a right angle, the kama is an extremely efficient tool for cutting all manner of grasses, and cereal crops, as well as leafy crops such as spinach, lettuce, and rubharb. Modern versions of the timeless kama, nowadays made with resin handles and plastic sheaths for the blade, are still used by Japanese gardeners and farmers for a wide variety of cutting needs.

But outside of Japan, the kama is perhaps best known as a martial arts weapon, especially in karate, where it is one of the five major weapon styles along with the bo, nunchaku, sai, and tonfa - all variations of farming tools which were secretly turned into weapons by the resourceful Okinawans because possession of swords by the common people was outlawed. The kama was also the weapon of choice for the ninja, due to its easily concealed small size and its innocent appearance as a common farming implement.

Used as a weapon, the kama has many assets. Typically used in pairs, the backward curving blade of the kama lends itself to all manner of slashing, hooking, thrusting and blocking maneuvers. The kama is particularly useful in rapidly disarming an enemy by hooking the blade or shaft of his weapon, and can also quickly cripple by hooking around and slicing an arm, leg, wrist, or ankle. When used for combat, kama are often attached to a long weighted chain to form a powerful combination weapon known as the kusarigama.