Jiu jitsu is a martial art that originated in Japan and has a long and storied history. However, the form of jiu jitsu that is most commonly practiced today is Brazilian jiu jitsu, which was developed and popularized in Brazil in the 20th century.
Japanese jiu jitsu, also known as jujutsu, is a traditional martial art that involves using throws, joint locks, and strikes to subdue an opponent. It was developed as a way for Samurai warriors to defend themselves in close combat situations where they were not armed with a weapon. Japanese jiu jitsu techniques were also used by law enforcement to apprehend and detain suspects without causing serious injury.
Brazilian jiu jitsu, on the other hand, was developed by the Gracie family in Brazil. The Gracie family was introduced to a Japanese judo master named Mitsuyo Maeda, who taught the art to Carlos Gracie. Carlos Gracie and his brother, Hélio Gracie, went on to develop and refine the techniques of jiu jitsu, creating the style that is now known as Brazilian jiu jitsu.
Brazilian jiu jitsu differs from Japanese jiu jitsu in that it places a greater emphasis on ground fighting and submission holds. It also has a strong competition aspect, with organized tournaments and competitions held worldwide.
So, to answer the question, jiu jitsu is both Brazilian and Japanese in nature. It has its roots in Japanese jiu jitsu, but the form that is most commonly practiced today is Brazilian jiu jitsu, which was developed and popularized in Brazil. Regardless of its origins, jiu jitsu is now a global martial art with practitioners all over the world.