In the distant future of 2356 A.D., a catastrophic supernova had caused a global disaster that wiped out 99% of the world's population almost two centuries ago. To monitor space activities, humans have constructed massive space stations known as "foundations" across the entire Solar System. Shima Katase, having successfully passed the Space Academy entrance exams, sets her sights on Stellvia, the Earth-based foundation, to pursue her ultimate aspiration of exploring the galaxy and averting another interstellar disaster that could devastate the Earth.