Ninja refers to the use of ninjutsu, stealth into the enemy, castle spies. They were most active from the end of the 15th century to the end of the 16th century, during the Warring States Period when generals from all over the country were competing for power.
Ninjas disguised themselves as outsiders, used tricks to deceive each other, and carried out espionage activities loyal to their masters.
Ninjas used many special weapons and items, such as "Shuriken" - small swords designed for throwing; Carry the Kunai - a double-edged sword shaped like an iron and used as a survival knife; Wear snowshoes to support the "water spider", you can walk on the water, etc.