After the events of My-Otome, Arika has become a skilled Otome under Miss Maria's guidance, while Nagi is imprisoned in a Aries facility. One year later, a proposed peace conference, S.O.L.T., aims to regulate the number of Otome worldwide. However, a mission to prevent a meteor from striking Earl sets off a chain reaction, including the emergence of a new, powerful Slave and a mysterious figure attacking Garderobe and Otome.