This story takes place on Earth 150 million years ago. At that time on Earth, various aliens were living in harmony by accepting each other under the God of the Earth, Elohim. However, one day, a huge meteorite flies toward the Earth at high speed. Before the meteorite hits the earth, a female soldier from the planet Vega, Yaizael comes and she narrowly protects the earth from destruction. It was actually a plan to annihilate the earth by Dahar, who is from the dark side of the universe... What will happen at the end of the battle for the survival of the Earth that involves the entire universe? (Source: lawsofuniverse-elohim.com)

Tekkaman is just an average bright boy in his everyday life. However, modern science can turn him into a mighty space warrior. This becomes a reality when aggressive aliens come from space to invade our planet. Armed with a space lance, Tekkaman gallantly goes into action against the grotesque space creatures. During his battles he encounters a mysterious young man from another planet who helps him out whenever he is in danger. (Source: Absoluteanime)

The first OVA, Burning Clock, tells the story of the Aiba family, goes into further detail about Shinya and Takaya's rivalry.

University students, Ray, Anna, Tyler, Halle, and Eisuke are enjoying college life and pursuing their dreams, but in reality, They have a secret mission, to fight against invading Reptilians from outer space. One day, Ray travels back in time to 330 million years ago on Earth, to find his missing friend Tyler who has fallen into a trap set by the evil alien, Dahar. During that time, Alpha, the God of the Earth, was planning to create a new civilization on Earth and invited Queen Zamza and her fellow Reptilian from the planet Zeta, to Earth. What is the intention of Dahar? What will happen to Ray and Tyler? And what is “the plan of the God of the Earth? (Source: Eleven Arts)