The user turns back for a brief second and does a leaping kick forward. This move has good range, and can hit some aerial foes (at certain angles), but is weak to being blocked. When blocked, the kicking animation is increased slightly and leaves the user vulnerable to counter-attack (or an Alpha Counter if timed right). The move is often considered an "approach", or move that helps Charlie/Guile attack foes directly.
In Street Fighter Alpha 3, the move can be used going forwards or backwards, interestingly, as opposed to just forward.