Ao is an extremely normal first year student in high school. When Frame Arms Girl Gourai is accidentally delivered to her, she boots it up. As a result, she becomes the only person in the world to have a Gourai model. Ao is completely in the dark when it comes to Frame Arms Girls and plastic models, but she learns that if she battles, she can win prizes. So, she decides to treat it like a part time job and tries out a test battle with Gourai.
(Source: Honey's Anime)