The purpose of Koryu no kata
First I have to mention, koryu no kata are practice kata rather than actual fighting kata.
There are 6 koryu no kata with each a different purpose. The origin of some koryu no kata can be found in Daito Ryu Aiki Jujutsu or other Japanese martial arts like Kito Ryu or Ryōi Shintō-ryū. Besides the many tai-jutsu waza (unarmed skills) some weapon skills are incorpared into koryu no kata. The weapon skills can vary depending on the weapon school of the chief instructor (shihan).
1.Dai Ichi no kata – basic waza based mainly upon prewar teachings of Morihei Ueshiba
2.Dai Ni no kata – an extension of Dai Ichi, more close quarters combat waza
3.Dai San no kata – partly based upon prewar teachings of Morihei Ueshiba & weapon skills. See also jo-no-tsukai
4.Dai Yon no kata – in general explained as applications of “kuzushi”. But explained in an alternative way as a skill to control the power of Uke.
5.Dai Go no kata – a study of “sen” and “hyoshi” based upon Dai Ichi and Dai Ni
6.Dai Roku no kata – influence of Kito Ryu originated from Ryōi Shintō-ryū. See also jo-no-tsukai.
In an old manuscript Budo Renshu,(1933), published with the help of Kenji Tomiki, many techniques are similar to Koryu no kata.
Suwari waza or sitting techniques give the opportunity to practise without the help of the legs. Kyokotsu, koshi and tanden will do their job to create efficient technique.
Section A starts with oshi taoshi. It is also called ik-kyo or ik-kajo, first principle or first technique.
Budo Renshu (1933)
Technique 1 (Koryu no kata dai ichi – suwari waza no.1)
Shi (Tori) : Using the right hand, strikes for the face of his opponent and with his left thrusts to the armpit at the same time raising his body (Koshi) (to the Kiza position).
Uke : With his own right hand blocks Shi’s right handed attack.
Shi : At the same time as grasping his enemy’s right hand moves slightly forward on his left knee and pulling down with his own right hand uses hist left to suppress use’s elbow.