As Yoruichi's face shot to the left avoiding Jack's left jab, his arm retracted swiftly and was immediately positioned as regularly. Jack's gaze shifted down on her entire body as she had avoided his punch, thus noticing the right leg coming around in attempt to kick Jack's left leg. In response, Jack shifts his stance slightly to his left by twisting his left leg and having his left knee cap face directly towards Yoruichi's oncoming right foot. Simultaneously to that notion, Jack also raises his right leg off of the ground and kicks forward, albeit, slightly upwards towards Yoruichi's thigh(Just above the inner part of her knee) with the dorsal part of his foot, breaking the moment of her kick as well as deal damage to her right leg. Prior to this, the left knee, even should Yoruichi's kick land slightly, Jack's left leg would not be bent or otherwise unable to maintain Jack's balance. As soon as the kick is delivered, Jack would retract his right leg, place it back into position and maintain his stance.
Note: Not to sure if I should respond to the rest of your move or not, but judging by the change of events. I take it your move would change entirely. If not...
As Yoruichi would twist to the right, gaining momentum as she swiftly delivers a left handed punch towards Jack's right cheek, Jack shifts his head a mere couple of inches, with his right hand following, as soon as Yoruichi's left hand would be relatively close to Jack's right hand instead of right cheek, he opens his right hand, brings it around on the inside of Yoruichi's left hand and grabs Yoruichi's left wrist. He then forces her punch and throws her momentum to his right side as he extends his right arm towards his right. Simultaneously to that, Jack performs yet another left handed jab into her throat and once again he would retract upon contact, in quick succession.
"I like your hair, but you have no radiance in your smile...so no, cougar."