Japan for the Uninvited

Ninja (or “shinobi”) were spies and assassins, highly-trained in ninjutsu (“the art of stealth”).

Most ninjas lived in secretive and carefully-guarded ninja villages (“shinobi no sato”) and were hired by the powerful elite for bodyguarding, espionage and assassinations.

They followed a code of honour called the ninpo. The most important rule was to protect secret information about the ninja or their employers, at any cost. Those who betrayed or killed other ninjas, or tried to abandon their village, would be hunted down and executed.

The ninja’s arsenal included disguises and camouflage, shuriken (ninja stars), gunpowder, traps and poison. They did not use black suits, nunchaku or karate (which wasn’t introduced to mainland Japan from Okinawa until the late 19th century).

• Ninja (Wikipedia)
• Enter the Ninja
  Some serious information, some proudly silly
• Ninja villages and museums in Japan (About.com)