Space Symphony Maetel: Galaxy Express 999 Side Story

Maetel abandoned her mother and her home planet, the doomed and frozen La Metal, where people must become cyborgs to survive. When she is beckoned to return, her options seem slim: follow her mother's path (and with it a robot mind and the contempt of all humans), or run away and fight with humans against the machines. Yet, she is not without comrades and defenders. (myanimelist.net)