Isshin-ryu kusarigamajutsu

is a traditional school of the Japanese martial art of kusarigamajutsu, the art of using the chain and scythe (kusarigama). Its exact origin is disputed, and may have been founded as early as the 14th century by the samurai Nen Ami Jion 念阿弥慈恩 (b.1351-?), but the modern-day techniques were compiled and incorporated no later than the 17th century, by the unification (tan'isshin, 丹一心) of Harayuki Uemon Ujisada (原志右衛門氏貞), hence the name. It is preserved in Shintō Musō-ryū as a "heiden" (subsumed teaching).