Mirai Ninja was based on a Japanese movie of the same name, also produced by Namco. Both the game and the movie were released the same year.
The plot of the movie: A man's body and soul are stolen and used as part of a demon castle. What's left becomes Cyber Ninja. He teams up with the chi students whose cyber-earmuffs show matching red symbols. They fill their swords with ammunition, grab some neo-retro-cyber-antique guns and attack the demon robot expendable ninja squad. Each fight is won by whichever side uses more gratuitous special effects. They slay the Tron-like hover droids, who are destroyed in their shame. There's a showdown with a white-armored guy with dreadlocks, who is later reincarnated by the eclipse and a lot of multicolored lightning. After killing the make-up wearing effeminate spider person, the chi school fires a giant gun at the demon castle spider cyber robot. It blows up.