In the year 2063, the possibility of space exploration has become a bona fide reality. Aries Spring eagerly anticipates attending a remote camp on the distant planet of McPa. Unfortunately, her excitement is rudely disrupted when a thief absconds with her purse at the spaceport. Fortunately, Kanata Hoshijima intervenes and recovers the stolen item. Kanata is a member of team B-5, a crew of youngsters who will accompany Aries on her journey. However, their excitement is short-lived, as a strange dark orb pulls the group into the vast expanse of outer space. Stranded and lacking the means of returning to Earth, they fortuitously discover an abandoned spacecraft that rekindles their hope. Nevertheless, upon inspection of their surroundings, they realize they are light-years away from their intended destination. The nine teenagers, now in a tight spot, must unite and utilize their meager resources to combat challenges and carve a path back home on their newly acquired vessel, the Astra. Though they are unsure of the cause of their misfortune, they work tirelessly to overcome whichever obstacles that lay ahead.