It is the age of Sengoku Jidai (the Warring States). The reign of the old Shogunate is over. Central authority has waned and many local clans have risen to power.
Shugo is a grand strategy roleplaying game. In Shugo you are part of a clan. You may be a general, an artist, a monk, a merchant, or an assassin.
Each clan is headed by a Daimyo or warlord. These Daimyo compete to become the new Shogun of Japan.