Arika Yumemiya
A main character of My-Otome. She enters Garderobe dreaming of becoming an Otome like her mother. She possesses the Blue Sky Sapphire (Souten no Seigyoku?), a memento from her mother.
Nina Wáng
A main character of My-Otome. As the top Coral student, Nina dreams to become a great Otome to make Sergay, her adoptive father, proud. She dislikes Arika from the moment they meet. Later in the series she receives the Ultimate Black Diamond (Shikkoku no Kongouseki?).
Nao Yuuki
Nao is a morally ambivalent red haired young woman with something of a cruel streak; in particular she enjoys tormenting Natsuki. She is also frequently associated with spiders and uses razor-sharp wires as her weapon of choice.
Erstin Ho
Arika's and Nina's roommate, from the country of Annan. Erstin mostly serves as a bridge between Arika and Nina, who don't get along very well.
Irina Woods
Irina is one of Arika's friends from the Aries Republic. She shows a love for technology and is under the tutelage of Yohko.
Tomoe Marguerite
She is Coral No. 2 and a room attendant for Chie. On the outside she acts normal but is jealous of Arika's and Shizuru's relationship.
Akane Soir
The top Pearl student and leader of the Trias. She becomes torn between her love for Kazuya and her dreams of becoming a Meister Otome. The GEM she receives upon appointment as Meister is the Pure Heart Malachite (Seiren no Kujakuishi?).