Ikken hissatsu translates as "one fist, certain kill," the idea being to kill an opponent with a single technique. In modern times, to avoid overly brutal applications, another interpretation used is "to defeat an opponent with one blow." There are two ways to achieve this high level of skill. The first way is to deliver a very powerful technique using one's kime. Kime (focus) is the synchronization of the entire body's energy to a single contact point at the moment of impact. In other words, it is the delivery of the strongest technique in the shortest time possible. It is kime that allows the karate student to master the finishing blow. Another way to achieve ikken hissatsu is to use a much less powerful blow, but to strike a kyusho point, or "vital" area. It is by applying these concepts that a smaller opponent can defeat a much larger one.
When considering the concept of ikken hissatsu, one can foresee the dangers of getting into a combat situation. Since the opponent may have the same idea in mind, before entering a fight, one must be prepared to die or to kill the opponent. Sokon Matsumura once said, "When two tigers fight, one is bound to be hurt. The other will be dead." These words remind us that even though someone may possess the ability to kill, fighting should only be used as a last resort, when no other choice is possible.
Makiwara ("rolled straw") is a striking post used by karateka to develop strong techniques, especially punches