"The Iwama Style"
Iwama Ryu is a style of aikido developed in the Japanese town Iwama, which the style is named after. A large part of the history of aikido as a whole stems from work done by O-Sensei Morihei Ueshiba in his dojo in Iwama, and the art split into several distinct branches after Ueshiba's death in 1969. Iwama Ryu was founded by his student Morihiro Saito (usually referred to as Saito Sensei by practicioners of the form), and is one of the more "traditional" forms of aikido, attempting to stay close to the original teachings of Ueshiba. It has sometimes been regarded as one of the "harder" forms of aikido, because of its heavy emphasis on training with weapons.
Saito Sensei was the student who spent the longest time training under Ueshiba, having studied under him for 24 years. Even while Ueshiba was still alive, Saito sometimes headed the instruction of classes, with Ueshiba watching (this was primarily during the last years of Ueshiba's life, when the old master's health was beginning to fail), which he was the only of Ueshiba's students to do while the old master was still alive.
The characteristics of Iwama Ryu Aikido are a somewhat "pedagogic" system of training emphasizing slow, patient gradual development in the students, a complete lack of any form of competition (although only the Tomiki aikido style appears to have adopted competitive practices), and lots and lots of weapons training. While the form also teaches taijutsu, the "body techniques", its masters stress that a comprehensive understanding of the martial art as a whole is vital for its practicioners' progress, necessitating training in all the three forms originally taught -- taijutsu, aiki-ken and aiki-jo. Use of weapons in aikido training deals more with forms of movement (and learning katas) than things like speed and force; skilled aikido practicioners always match the speed of their opponents, and apply understanding of anatomy and physical forces such as gravity to their advantage rather than their own physical strength. Iwama Ryu teaches the use of the ken (swords -- usually, wooden training swords known as bokken are used) and the jo (staves), the two weapons taught by Ueshiba in the 1940-1960's.