Wandering samurai Sanjuro finds himself in a rough gambling town run by two warlords and their hired thugs. While Sanjuro sets out to rid the town of all these pestilences by playing the two warlords off against each other, his efforts are complicated by the arrival of the son of one of the gangsters, who owns a revolver.
After a meteor strike, aliens attack Earth and begin turning people into zombies. Wannabe rocker Ace finds himself caught up in the carnage after rescuing his heroes Guitar Wolf, Bass Wolf, and Drum Wolf and becoming their blood brother. Is this legendary garage rock band the only thing standing in the way of the total destruction of Earth?