Jun's explanation of
irimi (enter) and
tenkan (turn), and
omote (front) and
ura (rear) are on the mark. However, the way I like to think of it is:
Irimi reverses
uke's attack/energy/ki back towards him.
Tenkan carries
uke's attack/energy/ki away from him.
In this sense, it does not matter if you are 'located' in
omote or
ura or 'moving' in
irimi or
'tenkan'. As David points out, there is
irimi in
tenkan and
tenkan in
irimi.
Both
irimi and
tenkan can result in throws, of course, but most people I see finish with an
irimi movement even when doing
tenkan (by my definition above).
Davids yin/yang comparison is right on the mark, but does not get at my original post that gestures that we need more training in
irimi than
tenkan. For me, as I stated, what we need is a method to train.
Irimi is what we want, and sometimes we need a bit of
tenkan to get us there.
Tenkan is what happens when
irimi fails so to train exclusively in
tenkan (like, we usually separate them and do two
irimi and two
tenkan techniques when training - in Aikikai) is not sensible. What we need is a method that brings the two together, forcing them to interplay in such a way that students can better understand and therefore, learn faster. The aim is to do
irimi, and
tenkan is a tool to help us get there.
As for David's last post - I think I'll have to read it again to make better sense of it
