Keiko Fukuda, the Japanese-born granddaughter of a samurai who learned judo from its founder and became the highest-ranked woman in the martial art, has died at age 99. Fukuda passed away Feb. 9 of natural causes at her San Francisco home, said her friend Shelley Fernandez. In July 2011, USA Judo conferred on Fukuda the rank of "10th dan," the highest level of mastery possible in the martial art. She was the only woman in the world and the only person in the United States to ever achieve that status. "Judo, it's not just a sport, it's a mental, physical and spiritual centering of your life, and it's an art and a science as well, and her life was totally in balance," Fernandez said.