The origin of Japan's martial arts is vague, and what we know of it, is more legend than truth. However, the takenouchi-ryu martial art system founded in 1532 is considered the beginning of Japan's jujitsu forms. The system's founder taught jujitsu in a structured and methodical manner.For the next several hundred years, the martial arts were refined by Samurai who made a lifetime study of some twenty or thirty martial arts. Of these arts only one was based on weaponless self defense -- jujitsu. By the mid-1800's more than 700 different jujitsu systems existed. The most popular were takenouchi-ryu, jikishin-ryu, kyushinryu, yoshin-ryu, mirua-ryu, sekiguchi-ryu, kito-ryu, and tenshin-shinyo-ryu; the last two were instrumental in Judo's development.