Agriculture is now stockpiling grain in to become a thriving, the difference of those who do not have a person to have a food is produced, the difference between the rich and poor, now born is also up and down relationship.
And reclamation of by the rice cultivation, a large labor force of scale in water management to use in paddy fields is required, the population along with it also will continue to large scale.
Ai deprives the right to use the arable land and water, often you will be conflict occurs in the population to each other.
By the vertical relationship of the integration and collective between populations through such strife, a small "country" is born in the country. Along with the rapid increase in population, came out also need to broaden the agricultural land, disputes between the populations is considered sprang.
In fact, it excavated a number of injury human bones that may have injured. Japan of these days, from the continent is referred to as the "Yamato", and conceded a tribute to the imperial court Himiko is Wei YAMATAIKOKU, we look forward to gold mark that is the king of Yamato instead.