Grandmaster (martial arts) of "Dan" rankings and Black belt and Red belt in martial arts both derive from Judo where they were adopted by its founder Kanō Jigorō. There are many terms similar or equivalent to 'grandmaster' used by various martial arts traditions. Some of these terms derive from older systems, while others are relatively modern. Japanese martial arts commonly use Sensei (先生) meaning "teacher" or literally translated, "born first" or "one who has gone before". A "Sensei" is a person who has knowledge and is willing to teach that knowledge to another. A "Sensei" assists students in "ken shiki" "the pursuit of
Japanese martial arts tools are constantly changing, requiring that the techniques to use them be continuously reinvented. The history of Japan is somewhat unusual in its relative isolation. Compared with the rest of the world, the Japanese tools of war evolved slowly. Many people believe that this afforded the warrior class the opportunity to study their weapons with greater depth than other cultures. Nevertheless, the teaching and training of these martial arts did evolve. For example, in the early medieval period, the bow and the spear were emphasized, but during the Tokugawa period, fewer large scale battles took place, and the sword became