The art of ninjitsu in contrast to Aikido is an art, designed to defeat your opponent at all costs. It takes its origin from Chinese style military tactics,animistic beliefs,esoteric Shintoist ideals,and bojutsu(staff fighting) Ninjitsu has three levels of development physical,emotional,and spiritual. The physical level of development includes body conditioning,stretching,endurance building. The emotional level envolves developing tolerances for pain(physical,emotional),hunger,controlling urges.Training at this level also envolves enduring extreme heat,and cold.