In that foggy city I learned a that no matter how civilized a society is in the end it is just a upgraded version of big fish eating small fishes. The only difference between a forest and civilization is that the big fish in civilization harvests small fish cleanly and letting new fish grow forming sustainable chain.
This also applies in this ninja world. A world that was just consider a cartoon is more or less similar to Earth the only difference is the existence of chakra and natural energy. In this man-eating world I was fortunate to be born as Uchiha and luckily i was just a child at the beginning of war.
With the advent of ninja village, the wars have gotten intense, the war started due to small territorial dispute, so Hashirama distributes the Tailed Beasts to create a power balance but fuck na! was Hashirama immortal? no! so you gave control of nuke to rivels so there will be peace what a logic. After Hashirama's death Tobirama Senju takes over as the Second Hokage and tries to maintain peace, but the First Shinobi World War begins anyway. In the end of war Tobirama Senju dies to protect his guard. Most sinoby village has suffered massive loss and next war 2nd ninja war is after 20 years.
I am 7 years old and i awakened my memory just two years ago when this bodies owner Kuroten Uchiha (what i was the name given by his parents meaning black heaven fuck no i the author gave that because its sounds cool) fainted due to the new of his parents' death in battle.
( I was thinking this natural energy might just be energy released by death of living being so it has will of dead so it is so hard to control)