From the Publisher:
In a Tokyo in the not too distant future a young girl studies deligently with ambitions of soon attending space academy. If things work out just right, her future may very well be among the stars as well. And yet, everytime she looks up to the stars with tremendous hope for the future, there is a sense of melancholy in her heart. A sadness surrounds Asumi, as the very concept of space exploration has profoundly changed her life for as long as she can remember.
In the ninth volume of Twin Spica, Asumi and her classmates are getting closer and closer towards graduation and the competition is getting fierce. There are some changes in store for this group of friends. There will be good-byes to be said and that might end up causing some difficulty within this group. Some of that might be spurred on from outside of the Tokyo Space School as the media has caught on to the identities of at least one prime candidate.
And then a person from Asumi's past just happens to show up in her dorm room one night. Asumi's relationship with this girl is not as tight as may be with Fuchuya or her other classmates, but she takes her in nonetheless. In her typical manner, she accepts Kasane almost unconditionally. Never asking her why Kasane has made her appearance, she invites her to stay even though it is clear that Kasane has been neglecting her own school responsibilties back in their home town of Yuigahara. There is no reason for Asumi to reject her, but she would like to know why now. The answer is obvious to at least one TSS student. And for someone who has struggled to make friends in the past like Asumi, it should be evident as well. So when Asumi does realize why, she makes sure to remind Kasane that their bond can survive through time and space.