Previous Position

Same leg position (Kokutsu Dachi) and Crossed Arm Strike with the Right Fist (Ura Zuki)

Feet Position on Diagram Facing Screen

 

Keep the legs in position
Bring the Left forearm back in front of your face until your Left fist is touching your Right shoulder.  At the same time, lower your Right arm down and bring the Right fist under the Left elbow  in an upper-cut motion, striking to the chin area

Breathe out partially and tense all your body muscles for a brief moment on the completion of the move
The next move should follow immediately