Kaeshi-uchi (trans. returning strike) has many variations.  The following video shows only three.  The strategic principle of all variations of kaeshi-uchi is to strike the opponent as he/she is attempting to strike you.  In the three variations demonstrated, the kaeshi-uchi is executed by striking the attacker’s lead grip on the jo (trans. short staff).  There are many tactical reasons for striking the lead grip but of significance is the effect such force has on the attacker’s capacity to remain mobile.  By striking the lead grip the attacker’s kinetic energy is aimed downward, as a result the attacker’s capacity to alter or reverse direction is greatly hindered.  The kaeshi-uchi thus acts as a check on the attacker’s Base of Support.  This helps to set up the counter tsuki (trans. thrust) to the pulmonary meridian.  This strike can then act as either a final blow or a blow that sets up a final blow.  For reasons of safety, the jo near the grip is struck instead of the attacker’s lead hand at the same time that the attacker seeks to the best of his ability to remove his hand from the target area.  In addition, the jo tsuki is delivered just shy of full penetration as the attacker uses a back-breakfall to remove himself from harm’s way. Uke: Sean Sanders - Shodan. (3 minutes, 35 seconds)