Aiki-jūjutsu (合気柔術), originally called Daitō-ryū Jūjutsu (大東流柔術), is a Japanese martial art that first became widely known in the early 20th century under the headmastership of Takeda Sōkaku. Takeda had extensive training in several martial arts (including Kashima Shinden Jikishinkage-ryū and sumo) and referred to the style he taught as "Daitō-ryū" (literally, "Great Eastern School"). Although the school's traditions claim to extend back centuries in Japanese history there are no known extant records regarding the ryū before Takeda. Whether Takeda is regarded as either the restorer or the founder of the art, the known history of Daitō-ryū begins with him.
Aiki-jūjutsu's history can be traced to the 11th century. The art was founded by a descendent of Emperor Seiwa named Minamoto no Yoshimitsu, who developed it through the study of human anatomy. It was passed on to the Takeda clan of Aizu, where it was secretly taught to samurai as a means of weaponless combat up until the fall of the shogunate in the 19th century.
In contrast to more aggressive fighting arts, Aiki-jūjutsu stresses non-resistance. Aiki practitioners turn an opponent's strength and motion against them, and use vulnerable points such as the neck, knees, and wrists as leverage. The goal is to harmonize your movements with an opponent's ki, or spirit. Redirecting attacks, counters, throws, and sweeps are all tools of the Aiki-jūjutsu trade.
A popular derivative of Aiki-jūjutsu is aikido, which was founded in the 1920s by renowned martial arts master Morihei Uyeshiba. After many years of training, Uyeshiba decided that the ultimate martial art would be one where neither the defender nor attacker would be hurt. This led to the development of aikido, which translates as "the way of spiritual harmony." This art uses sweeping circular motions that move in conjunction with an opponent. According to Uyeshiba, "Aikido is non-resistance. As it is non-resistant, it is always victorious."
- Aiki-jūjutsu at Wikipedia.