Shogun Assassin

One of the many different names for the Lone Wolf and Cub story. This particular name refers to the movie released in America with dubbed English voices.

While the Lone Wolf node will explain the saga, I will reproduce the famous intro to this movie here:

When I was little, my father was famous. He was the greatest samurai in the empire and he was the Shogun's Decapitator. He cut off the heads of a 131 lords. It was a bad time for the empire. The Shogun just sat inside his castle and he never came out. People said his brain was infected by devils. My father would come home, he would forget about the killings, he wasn't scared of the Shogun, but the Shogun was afraid of him. Maybe that was the problem. Then, one night the Shogun sent his ninja spies to our house. they were supposed to kill my father, but they didn't.
(woman screams)

That was the night when everything changed.

Shogun Assassin (1980, released by Roger Corman's New World Pictures) was many Americans' (and other English speakers) first glance at the excellent "Lone Wolf and Cub" series of Japanese sword films based on the manga by Kazuo Koike (story) and Goseki Kojima (art)—the original stories taking up some 8000+ pages.

The film took a somewhat cut version of the second film in the series (1972's Baby Cart at the River Styx) and edited in some 10 minutes of footage from the first (Sword of Vengence, same year). Then there was English dubbing and added "narration" written from the Daigoro's (the titular "baby") point of view (there was no such narration in the original series). Some feel that the editing destroyed the artistic lyricism of the battle scenes (directed by the underappreciated Kenji Misumi) and that the new score is poor compared to the original.

Technically not the first introduction of the series, as the third film (known variously as Baby Cart to Hades and under the literal title Perambulator Against the Winds of Death among others; again 1972) was released under the title of Lightning Swords of Death by Columbia Pictures in 1974. Again with edits for violence and English dubbing. The intention was to capitalize on the then-current Kung Fu craze.

Interestingly, the Leonard Maltin review (surprisingly quite positive) refers to Shogun Assassin as a "sort of a sequel" to Lightning Swords of Death. Well...sort of.

(Sources: David Desser's essay in Reframing Japanese Cinema, 1992, as well as his class on Japanese Cinema at the University of Illinois; "Cult Movies" issue 12; notes included with the videotape of Baby Cart to Hades)