I think If you source the two forces correctly (Aiki-sage and Aiki-age) it makes your partner unconciously "want" to hold on to your wrists.
Hi Jeff! I think this making your partner *want* to maintain their grip is important. I think what Mike calls the "suit" comes into play here as well, but I'm not far enough along to describe it well. Things that can play into uke keeping the connection:
The correct amount of startle affect (this can weaken the training of the other aspects though...when training slowly to work on other aspects, you don't really have the benefit of this)
A kind of magnetic or sticky feeling for uke when they grab you...any further suggestions for how to develop that feel outside of the technique??
A feeling of where you are grasped kind of "expanding" or pressurizing to fit uke's grip.