Aiki-ken
Aiki-ken (Kanji: 合気剣 Hiragana: あいきけん) is the name given specifically to the set of Japanese sword techniques practiced according to the principles of aikido, taught first by Morihei Ueshiba (aikido's founder), then further developed by Morihiro Saito, one of Ueshiba's most prominent students. Currently, Iwama Shin-Shin Aiki Shuren-kai is the main proponent organization. Development. Much of the aiki-ken syllabus was developed by Morihei Ueshiba (植芝 盛平 "Ueshiba Morihei", 1883–1969) at his dojo in Iwama, Japan, at the same time he developed aikido's staff training (called "aiki-jō"). It is well documented  that Ueshiba studied several different styles of "kenjutsu" (Japanese swordsmanship), but the aiki-ken techniques are predominantly based upon the teachings of the Kashima Shintō-ryu. The practice of aiki-ken is not pervasive. Some schools of aikido incorporate weapons training that is unrelated to aiki-ken, and others forego weapons training entirely. Practice. Much of aiki-ken bears little similarity to other modern sword arts. Rather than learning to "fight" with swords, the primary purpose of aiki-ken is to magnify errors in one's aikido technique, and to give the student an opportunity to apply the principles of  aikido in different situations. Aiki-ken is practiced using "bokken" (a wooden katana) and has a wide variety of techniques. Saito codified two sets of techniques, the first being seven "suburi" (solo cutting exercises), and the second being five partnered forms. Some dojo also practice "jiyu-waza" armed with "bokken" (freestyle technique, without a predetermined form of attack and response). Suburi. , meaning "practice-swinging", is used to refer to the basic solo movements of aiki-ken, developed as a distillation of the partnered practice. There are seven aiki-ken "suburi" in Saito's tradition, and are very simply named as  follows: Kumitachi. The partnered forms practice of aiki-ken is called , meaning sword practice with a partner. There are five "kumitachi" in Saito's aiki-ken curriculum. The "kumitachi" teach students how to alternately control the center line and move off it to avoid attacks and how to blend with an opponent's attacks, among other skills. Improvisational variations on the "kumitachi" (called "henka"), which generally cause the "kumitachi" form to end early with one person taking advantage of an opening to strike or throw the other, are also taught.