The story revolves around Sally's search for her grandfather Dr Borman, a researcher who worked on the Zi-Forming scheme. He bestowed her a pendant at the start of the series, with instructions to never hand it over to the Empire.

A competing researcher for the Empire: Dr Land seeks to find Sally's pendant.

The pendant is shown to possess strange powers, transforming Leo's Zoid into the Beast Liger, and later interacting with Regeneration Cubes - artefacts left over from the failed Zi-Forming scheme.

As Leo, Sally, and their comrades journey, they begin to uncover more of what the pendant can do, the relationship between the two scientists, and how it all relates to the Zi-Forming of Earth.