From the 14th century, ninjas was having lots of duties because of the repeated struggles in these ages. Lots of types of skills were made in these age too. All these skills had different names.

This is a list of ninjas that served the famous warriors in history. From this list, we can know that ninjas were the one that had made all the tactics that were used these days. In 1592 to 1598, Hideyoshi Toyotomi had tried to make Korea in their hands (which is called the “Cho-sen Shuppei”.). He had used information that ninjas got from their enemies in this war too. For example, a Nanjing man called Cho-ko (Sonjirou, as his Japanese name), had made his base in the domain of Satsuma (which had become Kagoshima prefecture now.), and had connection to Japan, Korea and China.
In the “Cho-sen Shuppei”, he had join Yoshihisa Shimazu’s army in the front, but behind, he had a connection with Korea and China. Moreover, in the domain of Satsuma, people from Korea and China came via the domain of Ryu-kyu (which had become Okinawa prefecture now.).

From the 17th century, ninjas had no chance to use their skills and tools because from this period, a peaceful age will start. They sold things such as medicine or went back to their home town.

An intelligence network opened by the development of the traffic steadily in modern (Meiji era - 1945). Then the aviation network developed in modern (1945 ...) more and more, and a foreign country became the world that was not far. In this time, there were not really the people who were active as a ninja anymore. However, a spy appeared in Japan as the people specialized espionage. We will not explain about the spies here, but armaments or the military power of the enemy country beforehand and make use for war and diplomacy. In addition, it is said that a spy is generally in the nation in the present age, but after all does not understand the real nature exactly.
Furthermore, it published a novel and special effects movies about ninja came to be shown when it was past the Meiji era. After the war, movies and animated cartoons about the ninja are televised flourishingly and collect popularity at Japan and even abroad.