Military historian Hanawa Hokinoichi Wrote:In his Buke Myōmokushō, military historian Hanawa Hokinoichi writes of the ninja:

They travelled in disguise to other territories to judge the situation of the enemy, they would inveigle their way into the midst of the enemy to discover gaps, and enter enemy castles to set them on fire, and carried out assassinations, arriving in secret.

The ninja were stealth soldiers and mercenaries hired mostly by daimyos. Their primary roles were those of espionage and sabotage, although assassinations were also attributed to ninja. In battle, the ninja could also be used to cause confusion amongst the enemy. A degree of psychological warfare in the capturing of enemy banners can be seen illustrated in the Ōu Eikei Gunki, composed between the 16th and 17th centuries:

Within Hataya castle there was a glorious shinobi whose skill was renowned, and one night he entered the enemy camp secretly. He took the flag from Naoe Kanetsugu's guard ...and returned and stood it on a high place on the front gate of the castle.

Military historian Hanawa Hokinoichi Wrote:In his Buke Myōmokushō, military historian Hanawa Hokinoichi writes of the ninja:

They travelled in disguise to other territories to judge the situation of the enemy, they would inveigle their way into the midst of the enemy to discover gaps, and enter enemy castles to set them on fire, and carried out assassinations, arriving in secret.

The ninja were stealth soldiers and mercenaries hired mostly by daimyos. Their primary roles were those of espionage and sabotage, although assassinations were also attributed to ninja. In battle, the ninja could also be used to cause confusion amongst the enemy. A degree of psychological warfare in the capturing of enemy banners can be seen illustrated in the Ōu Eikei Gunki, composed between the 16th and 17th centuries:

Within Hataya castle there was a glorious shinobi whose skill was renowned, and one night he entered the enemy camp secretly. He took the flag from Naoe Kanetsugu's guard ...and returned and stood it on a high place on the front gate of the castle.