Ninja are often misportrayed in modern media. However, ninja were not the crazed murderers depicted in many modern movies. A quote from the one of the ninja's historical documents, the Bansenshukai, shows the more accurate truth of their lives and beliefs:
"The essential element for the ninja is a pure heart. If a ninja pursues the wrong course using trickery or plots his heart cannot be pure and his judgement will always be misguided, never permitting an honest course of action. If such a person uses ninjutsu for only his own benefit or for that of an evil superior, their actions will betray them, showing they were responsible. There may be initial success providing money and fame but they will tumble from their high pedestals before long. The heart of a ninja is pure and honest."
PERTINENT NINJA DOCUMENTS
A four volume work written by Hattori Hanzo Yasukiyo. Ninpiden translates roughly as, "Secret Teachings of Ninjutsu."
A three volume work written in 1681. Shoniki roughly translates as, "Correct Ninjutsu Memories."
The Bansenshukai is a ten volume work on ninjutsu written in 1676. Bansenshukai means, "10,000 Rivers Gather into the Sea." It was written by Fujibayashi Yasutake of the famous Fujibayashi ninja family.