Iaidō (居合道), abbreviated iai (居合), is a Japanese martial art that emphasizes being aware and capable of quickly drawing the sword and responding to sudden attacks.
Iaido consists of four main components: the smooth, controlled movements of drawing the sword from its scabbard (or saya), striking or cutting an opponent, shaking blood from the blade, and replacing the sword in the scabbard. While beginning practitioners of iaido may start learning with a wooden sword (bokutō 木刀) depending on the teaching style of a particular instructor, most of the practitioners use a blunt-edged sword called an iaitō or mogitō. Few, more experienced, iaido practitioners use a sharp-edged sword (shinken).
Practitioners of iaido are called iaidoka. (Full article...)