Gun Frontier

Gun Frontier (ガン フロンティア, Gan Furontia) is a Japanese manga by Leiji Matsumoto serialized in 1972. Since the original manga, there has been a published novel in April 1999, and a 2002 anime adaption of the series by Vega Entertainment Studios.

Plot
It is a harsh and barren wasteland, where the weak aren't allowed to dream. It is also a sacred land for true men, for there is no place a man can feel more alive. This is the Gun Frontier. Sea Pirate Captain Harlock and the errant samurai, Tochiro Ooyama arrive in the United States on the Western Frontier. Along with a mysterious woman they meet along the way, the two friends challenge sex rings, bandits, and corrupt sheriffs. They are searching for a lost clan of Japanese immigrants, and they will tear Gun Frontier from end to end until they find it.