"That's part of it. You can't hold back during practice because it will make you hold back for real. If you've got something with lots of sharp teeth baring down on you, you're not gonna have time to think about what to do. You just have to react."

He wheeled over to where the knife had been flung and picked it up. "The other thing you need to do is make the blade a part of you. You're treating it like it's something different rather than an extension of your body. Pretend it's just another part of your hand or arm." He shows, in slow motion, a more fluid jab with the blade.

Then he gives the knife back to Osomatsu. "Now let's try again."