Ninjas are enduring, iconic figures of Japan. They were active about 500 years ago during the country's Warring States period. And these days, they're thought to be long gone. But centuries later, one ninja is still with us. 84-year-old Masaaki Hatsumi is a successor of the Togakure school. He teaches a supreme form of self-defense to more than 100,000 students around the world, including FBI agents and army personnel. Hatsumi can easily fend off attacks from these tough disciples and make them unmovable using just one finger. What is the essence of his astonishing art? This program investigates the hidden power of this ninja master.