One year after the events of Mai-Otome, an asteroid on a collision course with Windbloom kingdom is destroyed—barely—by an international task force of Meister Otome. Subsequently a new and more powerful kind of Slave appears, along with a sinister black-robed entity—or entities—able to easily overpower the most powerful of Meisters. Not only this, but Arika and Mashiro’s troubled relationship is hindering the use of the Sapphire of Azure Sky—possibly the one weapon powerful enough to defeat this new adversary.