In the year 1999, crime has overrun Tokyo city, Japan. Hopelessly outmanned and outgunned, the Tokyo Metropolitan Police Force decides to set up a special taskforce to combat the dire situation. Codenamed “ZAC” (Zero-Section Armed Constable), this police department is designed for special missions. For this cause, the police scientists developed the "Bit Suits", three high-powered armors outfitted with the latest technology: Mars, Saturn and Mercury. In the first episode, a mysterious young man, Shinya Takeda, appears from nowhere and saves the day after using his own armor, the Jupiter Bit Suit. Following his victory, he joins ZAC, which starts to battle the evil organization Death Trap, ruled by Baron Kageyama, which manages to use the computers' will-power to gain world domination.