Tokiha, Mai

鴇羽舞衣

Also known as the "Meister of Tragedy," Mai was an exceptionally talented Otome a few years before the series begins, who mysteriously vanished one day in the Sprites Forest. Prior to her disappearance, she had been offered the position of #4 among the Five Pillars, but it was rumored that she had fallen in love with a young noble and was torn between these two aspirations. She was Natsuki's rival during their student days and is the older sister of Zipang's Tokiha Takumi.
She finally appears to Arika at the end of episode 22, living with the Cat Goddess, Mikoto, in the Black Valley. The valley is part of the Sprites Forest and actually exists in another dimension, though it frequently overlaps with her home world. It is later revealed that she was never actually torn between love and being an Otome; she had simply gotten lost while taking a walk and ended up in the Sprites Forest. In the forest, she is accidentally caught by one of Mikoto's food traps, and Mikoto accidentally swallows one of her Meister GEMs, making Mikoto her master.
In Mai-Otome Zwei, she still lives with Mikoto in the Black Valley, now called Mt. Nekogami, and has opened a Ramen shop in the newly formed town at the base of the mountain. Her GEM is known as the Fire Stirring Ruby. Her Element, Ignition, remains the same golden rings she had in My-HiME.