There are many giant space stations roaming in orbit around earth. Stellar Sanctuary 04 is one of those, and its purpose is to explore the wonders of the dense and mysterious space. The short handed staff hires Euphémia, the main character, to become part of the station's crew. However, it is also on this station that she will make a groundbreaking discovery with the four other members, as they discover the existence of a comet that might disrupt the very fate of mankind...