Like the rest of the series, Samurai Warriors 4-II is set during Japan's Sengoku period, an era of widespread military conflict and political struggle in which the country was divided among regional warlords from the mid-16th to the early 17th century. Players take on the roles of warriors from this age across its battles. The depiction is romanticized rather than strictly historical, giving expanded roles to figures who had little presence in the actual events.