Many of Japan's ''weapons'' can be traced back to at one time being used for Farming. The Kama was a type of instrument which would evolve in a fighting tool, especially in conquered Territories such as The Island of Okinawa and The Philippines. In the 15th Century, The Kama was a pair of hand-held Scythes. Each Handle was a flattened piece of wood, roughly 2 to 3-feet in length. At it's Top was affixed a crescent shaped, single edged Blade (roughly 1.5 to 2-feet in length. This Blade was very sharp. Two were needed for their original function. This was the cutting of Bamboo shoots and Rice Stocks. An applied swinging motion allowed for a Harvester to cut many Stocks with a single pass of The Crops. Many using The Kama could clear an entire Acre in just several hours.
When Japan occupied Okinana around the 16th Century AD. - they forbade all traditional Martial weapons. Many Farmers were as such at the mercy of their – at times, cruel Occupiers. As such, many of these Farmers began to adapt common Farm Tools into weapons. The Kama was one.
The general application was to use The Kama to ensnare a Sword. By using a ''sweep and catch'' movement, a Sword could be snared and removed from it's Owner. Additionally, The Kama could quickly ''end'' an attacker by a series of slashing motions. However, The Kama was not effective against Armor. The Kama would find it's way in traditional Martial Arts usage (as it currently is in Okinawan Forms as well as Japanese Ninjitsu).