This alongside a post in /yn/'s "discovery" thread made me think of a theory.
Madotsuki's parents separated when she was a child. Mado lived with her father (Masada), her mother lived elsewhere taking care of Mado's two half sisters (Monoko, Monoe). Mado was deeply attached to her father, a pianist who taught her to appreciate music even in it's simplest forms. Masada's spaceship is a place where Mado hears only his piano and his voice, something that a child might find comforting.
Masada was killed in a car crash when Mado was a teenager (that sort of fade to black that happens when you fall asleep in Masada's bed, followed by the crash), Shitai is Madotsuki's mental image of him after that crash: the corpse of her father laying on the asphalt, covered in blood; having dragged himself from the wreckage in an effort to live long enough to get help. Mado probably never saw the effects of the crash firsthand, but that scene was what her mind fabricated when the police told her that her daddy wasn't gonna make it.
Mars is a metaphor for the way the world felt as Mado entered into a spiral of depression, scabbed over memories of her father, the only refuge from which is a tiny space she can squeeze into. That space is filled with metal wreckage and a creature who plays a piano riff, with what appears to be a piano for a foot (perhaps the background music plus the sound it makes were the first piano riffs her dad ever taught her?). The creature cries forever, one great big metaphor, again, for Mado's feelings. It's a point of no return.
Mado gets sent to live with her mother and half sisters. Her depression is getting worse, and she's reaching the onset of Antisocial Personality Disorder at about 15 years old. The world is black and white to match her thinking-- either people empathize with her, or they don't. She resents her mother and sisters because she feels like they can't feel her pain. Monoe seems very fake and catty to her and keeps her at arm's length (the smile, teleporting her to different places). Monoe is always discontent with something trivial (the look on her face), and as Madotsuki's personality disorder progresses into a more violent and increasingly less empathetic stage, Mado begins to want to disfigure her and give her something to REALLY be unhappy about (stoplight image).
Madotsuki runs away from home at 17, only to turn up 2 years later living in section 8 housing collecting disability for having Antisocial Personality Disorder, which had evolved out of Borderline Personality Disorder. She hates the world, or at least cares very little for it, and feels like it owes her.
She takes a foray back into her childhood through her dreams, and witnesses all of this. She watches her depression, her confusion, her sociopathy all unfold in front of her. It catches up to her, and for the first time in years, she feels regret. So much regret, in fact, that she can't cope with it, and commits suicide.
EDIT: Derp derp I forgot to add what I thought of Poniko. With Poniko, I think she was Mado's very close friend until Masada died, after which Madotsuki drifted away from her. With the onset of Antisocial Personality Disorder came a vindictiveness that made Mado convince herself that Poniko had abandoned her, and turned against her, dehumanizing Poniko enough to hate her. This dehumanization manifests itself in Mado's dreams as Uboa. The world goes dark and suddenly her best friend seems like nothing but a monster.
Last edited 10/05/15(Sat)23:38.