Aiki-Jujutsu, originally called Daitō-ryū Jujutsu, is a real life 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 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. Takeda's best-known student was Morihei Ueshiba, the founder of aikido.
Aiki-Jujutsu can be broken into three styles: jujutsu (hard); aiki no jutsu (soft); and the combined aikijujutsu (hard/soft). Modern Japanese jujutsu and aikido both originated in aikijujutsu, which emphasizes "an early neutralization of an attack". Like other forms of jujutsu, it emphasizes throwing techniques and joint manipulations to effectively subdue or injure an attacker. Of particular importance is the timing of a defensive technique either to blend or to neutralize an attack's effectiveness and to use the force of the attacker's movement against him. Daitō-ryū is characterized by ample use of atemi, or the striking of vital areas, to set up jointlocking or throwing tactics.
Some of the art's striking methods employ the swinging of the outstretched arms to create power and to hit with the fists at deceptive angles, as may be observed in techniques such as the atemi that sets up gyaku ude-dori (reverse elbow lock). Tokimune Takeda regarded one of the unique characteristics of the art to be its preference for controlling a downed attacker's joints with one's knee to leave one's hands free to access weapons or to deal with the threat of other attackers.