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
Black company (Japanese term) a DVD titled "Black Kigyō ni Go-yōjin" (Beware of Black Companies) was released. The protagonist of the manga "ReLIFE" worked at a black company. In the manga and anime series "Warau Salesman" (Laughing Salesman), one of the victims/protagonist worked at Black Corporation and contemplated suicide before meeting the Laughing Salesman. Black company (Japanese term) A , also referred to in English as a black corporation or black business, is a Japanese term for an exploitative sweatshop-type employment system. While the term "sweatshop" is associated with manufacturing, and the garment trade in particular, in Japan black companies are not necessarily associated