Inspired by a real-life race that is still held annually in Japan, Samurai Marathon is a lively action pic with a samurai twist. In the late feudal era of Japan, a young ninja (Satoh) is operating undercover in the court of an aging Lord during a peaceful era of Japan that is on the brink of change. After the Lord challenges his lazy samurais to a punishing marathon to toughen them up, the ninja finds his loyalties put to the test. Facing impossible odds, this unusual band of characters is running a race to win or die.