As Uke, I have a kaeshiwaza ready for every Nage who does ryotedori tenchinage. It involves waiting until the last moment, about to go down, then putting an armbar on the upper arm with my leg on the way down, using the full weight of my body.

This works, but it requires a risky gambit: letting go early.

After watching me take tenchinage several times in succession as the group Uke, Sensei noticed that I let go early consistently which I seem to do subconsciously now. He informed me of a henka waza Nage can do before I do my kaeshiwaza. Intriguing.

After we sat down in seiza together with practice going on all around us, we discussed the physics of what he had in mind.

He went to throw me. Of course I not dare put an armbar on Sensei, but I do posture to do so. As soon as I let go of the upper wrist he gongs my head. I try again. Gong. I try again. A ringing slap across my face. As soon as I let go at any point he can strike me.

The alternative is to jump higher and to wrench Nage’s shoulder while hanging on to his upper wrist, or to wait until he has thrown, but this is less effective. This becomes Aikijitsu but it is always good to have any kaeshiwaza in mind for everything.