During the Tensho era, the young boy Watari and the old man Ji took up residence in the ninja village of Iga, where the ninjas were divided into two rival factions, the Hyakuchi and the Fujibayashi Sects. The leaders of each sect ruled with the threat of death, and eventually those who wished to break the status quo formed a third Akame Sect. Watari and Ji play an active role in exposing dark conspiracies swirling around Iga Village, trying to overthrow the tyrannical ninja rulers.

(Source: Mangapedia, translated)