The mystique of Japan’s once-feared covert warriors, spread by films and fiction, is embodied today in the world’s first winner of a master’s degree in ninja studies, who also grows his own crops, just as many of his predecessors did. The modern black-clad ninja is Genichi Mitsuhashi, 45, who says he realized that ninjutsu, or ninja arts, held the key to survival after he was held up at gunpoint during ...