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 followed by adding force to the attacker's limb for the purpose of unbalancing an attacker is an example of soft method. Soft method techniques are generally conceptualized as being circular. These definitions give rise to the often illusory distinction between "hard-style" and "soft-style" martial arts. In truth, most styles technically practice both, regardless of their internal nomenclature. Analyzing the difference in accordance with yin and yang principles, philosophers would assert that the absence of either one would render the practitioner's skills unbalanced or deficient, as yin and yang alone are each only half of a whole. Openings, initiative, and timing