The Ninja Nunchacku said to be used by the notorious criminal assassins. The Ninja Nunchaku was first made and used by the Japanese peasant farmers and was called a Kusarigama (chain and Sickle).
Furthur development with a weight at the end of the chain was attached to add another dimension to the weapon. The weapon is an unusual and rare find. There are many imitations to be had but this is the second in 70 years that I have seen for sale.
The art of handling the Kusari Gama is called Kusarigama Jutsu. A rare collectors item first developed during the Sengoku wars and the Muromachi period when the acquisition of additional rice lands by rapacious War Lords was at its peak.