Early development of the martial arts
As the feudal era advanced, the Samurai came to occupy the uppermost strata of Japanese society. Their principal duty was to learn and practice many martial arts, the skills necessary to fulfil their allegiance to the feudal lord for whom they were expected to fight and die.
There were numerous martial arts which the Bushi were required to learn: Kenjutsu (sword), Bajutsu (horsemanship), Kyujutsu (archery), and Sojtsu (spear) constituted the principal combat arts. A favourite saying among Bushi at that time was 'Master Eighteen Martial Arts'. Additionally, it was necessary that the Bushi learn a secondary system of combat techniques to support their armed fighting methods. These unarmed techniques were referred to as Kumiuchi and involved a form of grappling techniques which evolved from Sumo (combat wrestling). Throughout the feudal era, the distinction between armed and unarmed techniques became greater.