A ninja dojo in Littleton, Colorado teaches the authentic way of the ninjas. Kaizen Martial Arts can now claim direct lineage to one of the two living ninja grandmasters. Sensei Bensen of the martial arts studio has trained with Shoto Tanemura, who traces his ninja teachers back to Uryu Hangan Gikanbo, a sensei from 1558 Japan.
Ninjitsu is an ancient Japanese martial art that trains individuals in physical fitness, mental awareness, weaponry, and stealth. Ninja warriors in the 1500s are like the special operations unit of that time. At present, the special ops of the armed forces use the same ideas.