Iaido, approximately "the way of mental presence and immediate reaction", is a Japanese martial art associated with smooth, controlled movements of drawing the sword from its scabbard, striking or cutting an opponent, removing blood from the blade, and then replacing the sword in the scabbard. It was developed as a defensive method to counter surprise attacks and enemy raids in fifteenth and sixteenth century Japan.
The purpose of Iaido was to slay an opponent with one stroke of the sword immediately after unsheathing it. In order to create such a defense system, situations and circumstances of surprise attack were studied to devise a systematized way to use the sword effectively against many forms of attack.
The practice of this martial art requires a solemn spirit, extreme concentration, and skill. Every motion, such as the movement of the arms or legs and body, must correspond to the offensive motions of the opponent, and it is of utmost importance that a person follow the rules of discipline that have been carefully and thoroughly applied.
The secret of iaido is a calm spirit. With a tranquil heart you put your hand on the tsuka (hilt of your sword) - in a split second your hand moves to cut down the opponent and re-sheath the sword - then return to your composed mind.
The physical practice of iaido includes drawing, parrying and cutting motions, as well as various methods for returning the sword to the scabbard. Most schools teach iaido using pre-arranged series of motions, sometimes called kata, or “forms.” The motions are designed as defenses against attack by an imaginary opponent, and each form teaches several principals of correct sword handling.
The art of iaido is a traditional art. Its forms are hundreds of years old, having been passed down from instructor to student since their creation. The teaching and practice methods of our style are kept standardized by the Toei - Ryu Iai Batto Renmei, headed by Master Mikio Nishiuchi 7th Dan.
Our lineage is as follows:

Sawada Sensei

Nishiuchi Sensei

There are other Japanese sword fighting arts which differ slightly from iaido. Though every form includes blocking and cutting motions, everything that happens after the sword is outside of the scabbard is more accurately called Kenjutsu (sword technique).
Another Japanese sword art is called batto-jutsu. Batto-jutsu simply means “sword drawing art.” Most iaido schools practice only forms, but batto schools such as ours also practice cutting. They would soon run out of training partners if they cut one another, of course, so they use rolled straw mats, which have been soaked in water. The soaked mats are meant to provide a lifelike resistance to the blade.
Why in iaido do we put so much emphasis on drawing the sword ? This emphasis is one aspect that remains from the days when these techniques were used in armed combat. A fraction of a second, or a millimeter’s difference in position, could make all the difference to the outcome of a match with a sword. The swords were razor-sharp, so even being touched with a blade meant a likely death. Getting the sword out of the scabbard and into the correct position quickly was crucial.
By continually refining our technique we can improve concentration, develop physical skills, and learn about another culture’s historical martial art and training methods. Many practice iaido as a second martial art, to compliment the more physical style of empty hand martial art. As a first martial art, it is well suited to these who want to avoid over-exerting themselves, as well as to those who are collectors or aficionados of the Japanese sword.