The Aikikai is the original school of Aikido. It is centered on the Aikikai Foundation in Japan, and its figurehead is the Doshu. It is represented globally through the International Aikido Federation.

Aikido is a modern Japanese martial art that is split into many different styles, including Iwama Ryu, Iwama Shin Shin Aiki Shuren Kai, Shodokan Aikido, Yoshinkan, Renshinkai, Aikikai and Ki Aikido. Aikido is now practiced in around 140 countries. It was originally developed by Morihei Ueshiba, as a synthesis of his martial studies, philosophy and religious beliefs. Ueshiba's goal was to create an art that practitioners could use to defend themselves while also protecting their attackers from injury. Aikido is often translated as "the way of unifying (with) life energy" or as "the way of harmonious spirit". According to the founder's philosophy, the primary goal in the practice of aikido is to overcome oneself instead of cultivating violence or aggressiveness. Morihei Ueshiba used the phrase masakatsu agatsu katsuhayabi" to refer to this principle.