A Meister (in full a Meister Otome) is an Otome who has graduated from Garderobe and acquired a GEM. All Meisters serve a specific Master, usually a noble from the Otome's country of origin, although the Five Columns and Otomes serving in Garderobe as teachers and/or administrators (such as Maria Graceburt and Yukariko Steinberg) have the Founder Fumi Himeno as their Master.
In addition, current undergraduates have, under exceptional circumstances, served Masters in a capacity similar to that of a Meister. This happened during the War of the Dragon King as well as in the cases of Nina Wáng and Arika Yumemiya, who both began serving Masters whilst Coral (i.e. first year) students.
By way of an honorific, Meister Otomes are sometimes called by the name of their GEM.