CHIBA, Japan -- Who would guess that an unassuming single-story building in a nondescript Tokyo suburb serves as a training ground for ninjas?
Bujinkan teaches self-defense skills to students from around the world

Students and practitioners chant at the beginning of training sessions at the Bujinkan's main dojo in Noda, northeast of Tokyo, on Sept. 5. (Photo by Hiroshi Tanda)
CHIBA, Japan -- Who would guess that an unassuming single-story building in a nondescript Tokyo suburb serves as a training ground for ninjas?