In his youth, Danzō was good friends with Hiruzen Sarutobi. However, Danzō always felt inferior to Hiruzen, harboring a desire to surpass him. Shortly after the foundation of the village, Hiruzen and Danzō sparred, while a few of their future team-mates watched. During the First Shinobi World War, Danzō, along with his team-mates: Kagami Uchiha and Torifu