Re: Yukiyoshi Sagawa's Aiki, a true portrait of Transparent Power - Interview with Tatsuo Kimura Par
It seems to me there are (at least) three levels:
1. Ability to manifest aiki in exercises designed for that purpose.
2. Ability to manifest aiki in kata based on the techniques of aikido. (Actually a spectrum, from static technique to dynamic attacks.)
3. Ability to manifest aiki freely in an open, unrehearsed situation. (Under increasing levels of objective stress, such as more and/or meaner attackers.)
1 can be learned, to some degree, in a weekend. 3 is the study of a lifetime.