A specific trope focused on the popular concept that if Samurai are present within a given story, chances are that ninjas will follow, or vice-versa. The idea bases itself on the premise of the samurai and ninja of Japan holding to opposing ideals, and yet both being considered Badass by the general public for their seemingly superhuman feats, skills and philosophies, even to the point of being historically inaccurate, especially in anime/manga. Usually, one or the other is the protagonist while the other is the antagonist (usually though, the latter can be an army of Mooks.)