During the latter half of the 21st century, mankind departs from Earth to settle in outer space. To adjust to the space environment and battle Jupiter's unfriendly extraterrestrial inhabitants, scientists create genetically modified children known as "Princes." These youths are raised and educated to become skilled pilots of the formidable "AHSMB" armed robots. "Princes" like Hitachi O Izuru, a teenager studying in the academic center of Grandzehle, offer a glimpse into the lives of these remarkable space warriors.