The Kiso horse has inhabited Japan for about one thousand years and has in the past been an indispensable aid for farm use, transportation, and power. Exact origin of the Kiso and other ancient horse breeds of Japan is uncertain. They are believed to be descended from either the plateau horses of Central Asia or the Mongolian horses of the grasslands.
Japan uses horses for military purposes as well as in agriculture and transportation.
In the twelfth century, the warrior Yashinaka Kiso reportedly had 10,000 horse soldiers. Kiso canyon belonged to the Owari feudal clan. Records from this time regarding the ancient types have been a valuable aid to modern horse breeders. Because Japanese horses are generally small in size, the authorities discouraged breeding purebred Kiso and encouraged a crossbreeding program between the Kiso and larger western horses. During the period surrounding World War II a government program was administered for the purpose of castrating purebred Kiso males.