Natural disasters have devastated planet Zi, killing off almost all life. A thousand years later humans have gradually re-established civilization, salvaging ancient Zoids through diving and mining efforts. In a village whose most previous item is a giant sword which they worship as a holy symbol. A teenage boy discovers an ancient Liger-type Zoid while on a deep water salvage operation. Suddenly the village is attacked by skeletal Bio-Zoids intent on stealing a powerful generator located in the village. Our teenage hero awakens the Liger and discovers that the town's sacred sword is the Liger's weapon, together they fight off the mysterious Bio-Zoids. At least for now...
New Century Zero takes place a long time after the events of Zoids: Chaotic Century. Zoids are no longer used for warfare; instead the combative natures of both Zoids and humans are focused and contained by a series of battle-competitions and tournaments, run by the Zoid Battle Commission.
The Zoid Battle Commission seems to be a significant power on Planet Zi, fielding a considerable arsenal of armed Zoids, orbital platforms serviced by their own launch facilities as well as orbital based weapons systems. It is not made clear in the series if the Helic Republic and Guylos Empire still exist, although the final battle upon the rusted Ultrasaurus, hinted to be same one in Zoids: Chaotic Century, could suggest neither were left and people had free rein to battle in old battlefields.
R.D. is a delivery boy who works for a company called Mach Storm in order to earn money to search for the legendary Alpha Zoid. A Zoid that he heard rumors about from his dad that he passionately believes in. Mach Storm also doubles as a Zoid Battling team. In R.D.'s first Coliseum Zoid Battle, he encounters a team that can fuse Zoids. R.D. soon discovers that he has a Zoid that can compatably fuse with his Zoid, Liger Zero. After this happens R.D.'s adventure to discover the truth about the Alpha Zoid begins.
Planet Zi, a world where warrior bio-machine lifeforms called Zoids live. They are controled by human pilots in a war with the Republic and the Guylos Empire. One day a boy named Van being cased by bandits hides in some old ruins, he finds two pods in a hidden room & opens one to find out its an odd dragon-like Zoid called an Organoid which he names Zeke. Zeke then ressurects an old dead blue Shield Liger Zoid for Van to pilot. When Van opens the 2nd pod a very mysterious girl named Fiona comes out of it. They go on the adventure to find more about her past & to find the Zoid Eve, they meet new friends & they get into some serious problems including the war which they try to stop.