The story begins when Ao opens a package that arrives at her doorstep. Inside the package is Gourai, a Frame Arms Girl: a small robot capable of independent movement. Gourai is a newly-developed prototype: a Frame Arms Girl equipped with an "Artificial Self," an advanced AI that gives her a personality. Ao is the only one that has activated her. Gourai begins to gather both battle data and emotions, starting a day-to-day life with Ao, who knows nothing about Frame Arms Girls. (Source: ANN)

Rick Wheeler was a police detective who got into a fatal car accident while pursuing the criminal Zoda. He was placed into artificial coldsleep for 150 years. Wheeler is brought back to life by Jody Summer and Dr. Stewart, who work with a group of good racers who try to keep prize money out of the hands of unsavory people like the Dark Million Organization run by Black Shadow and Deathborn.

One night, right before summer vacation, Manatsu Daichi, a second-year in high school, sees a weird round rainbow floating in the sky above Tanegashima and ventures there alone. He has seen this rainbow before. With the memories of his father's mysterious death and an encounter of a strange boy and girl, Daiji arrives on the island while the alarm of a building labeled Earth Engine is going off. Someone asks him if he is a captain, just as robotic intruders from Uranus called Kill-T-Gang arrive. The battle around the shining stars is about to begin.

An alien woman named Maya crash-lands on Earth. Her homeworld was destroyed by the Blasters, a cruel alien race who steals the natural resources from other planets. She falls in love with a scientist and gives birth to a human boy named Kentaro. When the Blasters invade the Earth, Kentaro must defeat them by fighting with Astroganger, a robot made from living metal. (Source: Wikipedia)