The oral tradition states that Muso Gunnosuke, the founder of Shindo Muso Ryu Jojutsu had mastered 3 styles of kenjutsu (sword fighting) and favored the sickle and chain weapon known as the kusarigama. 

From a historical perspective, the sword had to be thoroughly understood in order to devise methods to defeat it with the stick. In learning Jodo, proper training demands that the superior technician be on the sword (ken) side of training.  This individual is referred to as Uchidachi or simply as tachi. The beginner (kohai) is called shidachi.

In the days of Shimizu Sensei, there was discussion of the "lost" kata.  There were supposed to be 12 front (omote) and 12 back (ura) or hidden kata.  Over the years this has taken on a prophesy like status and some have invented kata quite recently to fill the void.  The movements are of questionable value and even more questionable bona fides.  Still, the kata that have survived are wonderul.  The weapon could be used at both long and short range.  Used for blocking, ensnaring, locking, striking, and cutting, the Kusarigama is extremely versatile.  

Training in the Isshin Ryu, like kenjutsu is supposed to come at a time when the student is already well versed in Jodo.  Today some teachers use the weapon as a marketing tool to attract the uninitiated and this is a shame.  Another assault on this art comes in the form of false claims about the history and mechanics of the art that has survived.  There was no sokei or hereditary headmaster, though today one Senior Jodo Teacher claims to be so and as written above, some newer "made-up" kata have been added to inflate the surviving curriculum.