Osawa Sensei moves his feet as if to do a katatedori kokyunage. He then immobilizes Uke‘s grabbing-hand, focuses on his own pinky finger and shuto, then cuts straight up along the contour of Uke‘s karada-no-omote, slides in deep along the direction of this cut, then pivots back and completes the cut-down (throw). As far as I know, he is the only person who does this, and uses hyper-extension to lift Uke‘s center before the actual technique is executed.

He continues to use this method of hyper-extension for the ura version too.