In the latter half of 21st century, humans leave the Earth and begin to live in space. In order to adapt to the environment in space and deal with the hostile aliens in Jupiter, genetically engineered children called Princes are artificially raised and trained to be pilots of armed robots AHSMB (Advanced High Standard Multipurpose Battle Device). This is a story about one of the teenage Princes, Hitachi O Izuru, who studies in an academic city Grandzehle. (Source: ANN)