Shinobi, often referred to as ninjas, were covert agents in feudal Japan known for their skills in espionage, sabotage, and guerrilla warfare. They were trained in various martial arts, stealth techniques, and the use of specialized weapons. The term "shinobi" is derived from the Japanese word "shinobi no mono," which means "one who endures." Shinobi played a crucial role during the Sengoku period, a time of constant military conflict in Japan. They were employed by samurai and feudal lords to gather intelligence, conduct surprise attacks, and carry out assassinations. Their mysterious and secretive nature has made them a popular subject in Japanese culture and media.