There are several modern schools of ninjutsu that claim to teach martial arts styles descended from the practice of ninjutsu, the historical arts of the ninja covert agents of feudal Japan. One of the earliest modern schools to be established was the Bujinkan Organization in 1978 by martial artist Masaaki Hatsumi. The organization teaches nine different martial arts styles, three of which are named after and claim to be descended from historical ninjutsu styles. Stephen K. Hayes, a student of Hatsumi, took what he learned to the United States in the 1970s, starting his own group of organizations called Quest Centers and his own martial arts style, To-Shin Do. Several other schools of ninjutsu also were created during the 70's, including the Dux Ryu Ninjutsu school in 1975 and the Nindo Ryu