Lilie is a member of Arika's class and one of Chie's room attendants. She, Miya and Yayoi are always hanging out together. She and Yayoi are made honorary Maki Maki members by Shiho. In the end, they're made Pearls along with Irina.  (Source: Wikipedia)

Arika Yumemiya has traveled far in search of her goal: the prestigious Gualderobe Academy. This is the school where young girls are trained to become Otomes, protectors of royal leaders throughout the lands. Here, Arika makes plenty of friends, but some enemies know something about her past that she does not. Nevertheless, her spirit and determination will keep pushing her forward. 
Adapted from its predecessor, Mai-HiME, this series is not a direct sequel, but an alternate universe setting featuring some of the Mai-HiME cast (though with different personalities).
 
(Source: Anime News Network)

My-Otome Zwei takes place one year after the events of My-Otome. Arika is now a full-fledged Otome (though still under the tutelage of Miss Maria) and Nagi is incarcerated in a prison somewhere in Aries. The various nations are at peace with one another and plan to hold S.O.L.T. (Strategic Otome Limitation Talks) to discuss limiting the numbers of Otome. 
A mission to destroy a meteor threatening to collide with Earl sets into motion a chain of events which result in a mysterious shadowy figure attacking Garderobe and several Otome as well as a new, more powerful version of Slave appearing across the planet. To make matters worse, Queen Mashiro disappears following an argument with Arika. The series follows Arika's search for Mashiro as well as Garderobe's attempts to uncover the truth behind the shadowy figure. 
(Source: Wikipedia)

Specials that followed on the Mai-Otome DVD.

Lilie Adean