Ninja are spies trained in a special kind of physical art called ninjutsu. Ninjutsu involves sneaking unnoticed into enemy camps or people's houses, disguising themselves so as to conceal their identity, using visual tricks to escape, and so on. Ninja served those in power and took on such missions as secretly finding out the strategies and military capabilities of enemies, destroying their weapons, and assassinating their leaders. Ninja were the most active in the Sengoku (Warring States) period, around the sixteenth century. They no longer exist in Japan today.
In the past, there are said to have been about 50 different schools of ninja scattered more or less across all of Honshu, Japan's main island. There are several places that are still known today as "lands of the ninja"; these are the areas where the different schools of ninja were based back then. The most famous places among them are Koka in Shiga Prefecture, formerly the home of the Koka-ryu ninja; Iga in Mie Prefecture, once home to the Iga-ryu ninja; and Togakushi in Nagano Prefecture, where the Togakure-ryu ninja lived. (Ryu means style.)
The ninja were known to travel across water, go underwater, climb over high walls, break into places without making any sound, and disappear in an instant. Naturally, they needed various kinds of weapons and tools to be able to do all these. Let's take a look at some of the places where the ninja lived and learn about who the ninja were and what kinds of weapons and tools they used.