A meteor strikes the Earth and is found to emanate a powerful new energy called Beamler, which is used to power a battle robot, GoShogun, and a teleporting fortress, Good Thunder. The Docougar Crime Syndicate, lead by crime lord Neo Neros, try to steal the secret of the energy from the inventor of GoShogun, but he kills himself rather than let them acquire it. His son is targeted by Neo Neros next, but he is taken in by the crew aboard Good Thunder, who travel the world fighting NeoNeros's forces with GoShogun. (Source: Wikipedia)

The story revolves around a girl named Yuuka, who encounters a being from the depths of the Earth named Chii-chan (a pun of chiteijin, the Japanese word for underground-dweller), and an alien named Ucchan (a pun of uchuujin or alien). The story follows their heartwarming and chaotic everyday lives together.

In the Kagami household, the old Western palm-sized mirror has been passed from from generations to generations. Akko-chan has been taught about the importance of the mirror and when she finally receives it from her mother, she cherishes it with all her might. One day, in the midst of a disturbance made by Taishou and his gang, Akko-chan accidentally broke the mirror. She made a grave and buried the broken pieces in the backyard. That night, Akko-chan was awakened by a flash of light and a kind voice which belongs to the Queen of the Mirror Kingdom. The Queen expresses her gratitude to Akko-chan for valuing the mirror so much and offers her a gift—a magical compact mirror. Whenever Akko-chan sings the magical words, she will transform into anything she wants. (Source: ANN)

Having failed the Comet Blaster exams mysteriously, Mikaze and her friends are sent back to the Shimoji Island base, where, with three new Meteor Sweeper trainees around, they have been promoted to instructor positions. Meanwhile, more comets are on their way to Earth, and the mysteries behind the rift in the Cosmic Emergency Management Agency—as well as the alien parasites—begins to unravel.