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 first joining with the motion of the opponent (the physical aspect) as well as the intent (the mental portion), then overcoming the will of the opponent, redirecting their motion and intent. Historically, this principle was used for destructive purposes; to seize an advantage and kill one's opponent. The modern art of aikido is founded upon the principle that the control of the opponent achieved by the successful application of "aiki" may be used to defeat one's opponent without harming them. "Kokoro" (心:こころ) is a concept that crosses through many martial arts, but has no single discrete meaning. Literally translating as