Peter A Goldsbury wrote:
... so I suspect that 5-kyou, like kaiten-nage, was added to the repertoire of kihon waza by Kisshomaru Ueshiba.
And then there is 6-kyou, which is a variation of 2-kyou, but where uke's arm is kept straight.
Best wishes to all,
I didn't know that fact about Kaiten-nage, but I can tell you that in 1989 my Yoshinkan teacher in Japan - a direct student of Shioda Sensei - told me there was no Kaiten-nage in Yoshinkan. I have since seen Yoshinkan people doing it ...
5-kyou: Consider this. Right handed attack comes. Avoid left and place your left hand on uke's wrist and you are setting up for kote-gaeshi. Avoid right and place your right hand on uke's wrist in the same way (mirror) and you are setting up for 5-kyou (amongst other thngs, of course). It is a mirror technique. If you remove 5-kyou it would be like taking away one side of a mirror. Does that answer "Gokyo-Why?" I wonder?
Also, your description of 6-kyou is Judo's wake-gatamte. I learned it in Tomiki, in the Institute of Aikido, in Kyushin-do, in Jujutsu, and in Judo. Everyone has it but Aikikai, although some do, calling it different names (rarely wake-gatame).