Hua-Saji Empire has been facing the invasion of combat machines for centuries. The only hope of defense is the hoods, war machines, which in accordance with the teachings of yin and yang can only be driven by pairs of man and woman. Girls usually do not survive the battle, but they are willing to sacrifice themselves to bring their families to their families. But if they survive, they will become an exception - an iron princess. Wu ze-tchien, a girl from a poor borderland, on noble ideals coughing. They see what is behind them: hundreds of dead girls who sell their families as cattle for defeat. When she decides to enlist herself, she has a single goal: to kill a pilot who murdered her older sister. She has no idea that there is a third option: to come out of the battle as an iron widow. Recommended age 15+