Samurai Warriors 4 is set during Japan's Sengoku period, a turbulent age when the country was splintered into domains ruled by rival warlords locked in near-constant war. Across its campaigns, the game follows the famous commanders and clans of the era through a romanticized retelling of history's great battles. Players witness the long struggle to unify the land, culminating in the decisive conflicts that gave rise to a new ruling order. A parallel path highlights the celebrated Sanada clan and its own place in these sweeping events.