The Huaxi Empire has been facing the invasion of war machines for centuries. The only hope for defense is the cocoons, war machines that, in accordance with the teachings of yin and yang, can only be operated by a pair of men and women. The girls usually don't survive the battle, but they are willing to sacrifice themselves to bring honor to their families. But if they survive, they will become an exception - the Iron Princess. Wu Ze-tchien, a girl from a poor border country, rejects lofty ideals. They see what's behind them: hundreds of dead girls sold by their families like cattle for slaughter. When she decides to enlist herself, she has one goal: kill the pilot who murdered her older sister. Little does she know that there is a third option: to emerge from the battle as the Iron Widow. Recommended age 15+