One year after the events of My-Otome, Arika is a full Otome, though Miss Maria still guides her, and Nagi sits in a prison in Aries. The nations are at peace and plan talks on limiting how many Otome each may have. Then a team of Meister Otome narrowly destroys a meteor headed for Earl. What follows is a string of events: a shadowy figure attacks Garderobe and several Otome, and a stronger new kind of Slave appears across the planet. After an argument with Arika, Queen Mashiro disappears. The strain between the two hampers the Blue Sky Sapphire, perhaps the only weapon able to stop the new foe. Arika searches for Mashiro while Garderobe works to learn who the figure is.