The game is set in 16th century Japan: an age of violence and opportunity.
The Shogunate of Ashikaga dwindled to an eight-year old boy.

Power devolved to the aristocrats of the Emperor's court -the
But without a strong center, they destroyed one another in war
and their authority in the provinces evaporated.

The resulting chaos is
gekokujo - "the low overturn the high".
During this period ambitious leaders arose from every rural hilltop
to challenge the power of the Shogun