The planet is about to be attacked by a pair of intergalactic fiends -- the evil robot Deathfacer and the nasty monster Queen Monera. Poweful heroes Ultraman Tiga and Ultraman Dyna must combine their skills to defeat the bad guys and save the day. Not wanting to rely on Ultramen to constantly protect them, several of Earth's scientists develop their own powerful weapon called the Neo Maxima Cannon.