It is a representative military art in Japan that includes ideas from the Zen sect (a Buddhist sect that strongly maintains the spirit of awaking through ascetic training in India) such as ho-shin (absentmindedness), shi-shin (adherence (to something)), mu-shin (a state of mind free from delusion), zan-shin (physical and spiritual alertness after delivering a strike or thrust), tan-shin (sincerity) and ren-shin (training the mind) with Shinto and Taoism and established them as an unique 'kokorone' (feelings) in Japan.
放心・止心・無心・残心・丹心・錬心など禅宗（インドの苦行開眼精神を色濃く残す仏教の一派）の概念を神道や道教などと渾然一体となし、日本独自の「心根」にした代表的な武芸である。