By Kou Yaginuma. Released in Japan as "Futatsu no Spica" by Media Factory, serialized in the magazine Comic Flapper. Released in North America by Vertical.
As we get into the third volume of Twin Spica, it becomes clear that one of Yaginuma's strength's is how to pace things out. I didn't get this at first, as when I finished the first chapter I felt that the whole 'Asumi runs away' was resolved entirely too neatly. But of course it's not resolved at all, as we see the teacher continuing to show bias against her once she returns - as well as seeing that he's been ordered to by higher-ups, for reasons unknown. For once, we're reading a 16-volume series that feels like it's been plotted out to 16 volumes in advance, rather than one where the editors said "this is a hit, can you add 12 plotlines?".
One plotline that I'm surprised we haven't seen yet is the student bullying. Perhaps because Asumi is bullied enough by her teacher, the students here seem to stick together. Not just her circle of friends, either; we see a great scene where the students are all put on a spinning, revolving wheel of death and forced to do math. Asumi, of course, handles the g-force with ease, as we have already seen that physically she is badass. If tiny. When she finishes, the other students crowd around to congratulate her and wonder how she can do such things. They also join Kei is protesting the teacher's bullying of Asumi. They're the anti-Gakuen Alice students. (At least so far.)
And a lot of this volume is devoted to showing us that even the cold or 'villainous' characters are just human beings after all. Not only is Sano, the aforementioned teacher, being told to try to get Asumi to quit (which to be fair he doesn't push against too hard), but he then resigns after a brief crisis of faith (involving some backstory for The Lion, the tragic accident that powers much of this series). Asumi comes to realize that he, just like her, is a dreamer who wanted to see humanity get into space, but was simply crushed by events. The best art in the volume shows her confrontation with Sano as he leaves the school, showing that she knows what he's dreaming of.
We don't get Mariko's backstory here, beyond her clearly being rich and lonely, and her parents being very overprotective and wanting to isolate her. But that's enough for now, and she certainly remains one of the characters I want to see more of (I will admit that their other friend Kei, who is likeable enough, I don't really feel the same way about.) Mariko needs to open up, and starts to do so here a bit, overpowered by Asumi's basic niceness (at times this reads very much like a shoujo manga).
There's more main story here, so we only get one 'side story' starring Asumi as a child. This one being a very melancholy tale from her middle school days of her brief friendship with a sickly boy who is the only one besides her that can see Mr. Lion. However, I'm definitely more into the main story by now. I want to see Asumi do more spaceflight stuff, and see more of Mariko. And I definitely want to find out why the higher-ups in the school seem to have it in for Asumi. Is it entirely related to her father's work on The Lion? In any case, this series continues to be almost impossible to put down.