The project went through a turbulent and prolonged pre-production period, going through multiple revisions until its final version began development in 2014 for PlayStation 4. Nioh began development in 2004 for PlayStation 3 as part of a multimedia project based on an unfinished Akira Kurosawa script. Gameplay revolves around navigating levels and defeating monsters that have infested an area combat revolves around stamina or 'Ki' management and different sword stances that are strong or weak against different enemies. Adams pursues the sorcerer Edward Kelley into the final battles of the Sengoku period during Tokugawa Ieyasu's efforts to unify Japan, an effort complicated by the emergence of yōkai that are flourishing in the chaos of war. Set during a fictionalized version of the year 1600, the plot follows the journeys of William Adams, an Irish sailor named after and inspired by the historic William Adams, an Englishman who became a samurai.