The game's hero, Gekkou, is a young ninja who lost his father to a mysterious half-man half-beast creature. The plot of Ninja Spirit is based on the quest of his revenge in an alternative feudal Japan.

The game's hero, Gekkou, is a young ninja who lost his father to a mysterious half-man half-beast creature. The plot of Ninja Spirit is based on the quest of his revenge in an alternative feudal Japan.