Aiki (martial arts principle) and its practice is often kept within a particular individual or two from a family/school lineage. Culturally, and due to certain necessities of the time period, the aiki knowledge was usually a very well guarded secret and rarely disclosed. The oldest book to have historically discuss aiki was the 1899 Budo Hiketsu-Aiki no Jutsu. On the subject of aiki it was written: The Textbook of Jujutsu (Jujutsu Kyoju-sho Ryu no Maki) from 1913 wrote: Aiki (martial arts principle) Aiki from a Japanese budo term, at its most basic is a principle that allows a conditioned practitioner to negate or redirect
Budo: The Art of Killing in Japan. Aikido is then demonstrated by Gozo Shioda, the founder of Yoshinkan aikido interspersed with shots of leaves falling into a brook. To emphasize the film's theme of "mind and body are one in Budo" the viewer is shown Shinto practitioners fire walking. The film then shows training in a sumo stable with rikishi Takamiyama, where the training shown is both tough and cruel. Scenes of young people practicing kobudo on the beach follow the sumo demonstration as the narrator discusses the succession of Budō to younger generations. The film explains the importance of kata with Teruo Hayashi demonstrating