In Super Street Fighter IV some special moves can be preformed by canceling of of normal moves. Some of them even allow certain characters to extend their model range, allowing them to grab opponents from further away, or to preform special moves with extended range.
Notable examples of Kara moves are Ken’s kara-grab, Sagat’s kara-uppercut and Akuma/EvilRyu/Oni ‘s raging demon. Here is a video tutorial explaining how to execute Oni’s kara-demon through normal moves.