Nina Wáng the top student in the Coral class and also one of Arika's roommates. She hails from Artai, a poorer kingdom than Windbloom with no Otome of its own. She and Nao are intended to fill this void and serve their country after graduating. Her father is Sergay Wáng , Nagi's right-hand man who is also part of the military. Arika found out that Nina was very sensitive to being tickled, which she enjoys exploiting. Nina is serious, determined and hard working because she wants to win the love of her adoptive father Sergay. Nina holds mixed feelings towards Arika. She is jealous of Arika's connections with Sergay and often annoyed with her cluelessness, but she shows friendship towards her on occasion. Nina's friend, Erstin Ho, was also her roommate who was in love with her.

Nina actually is daughter of Sifr Fran, the previous Windbloom Queen.
Her first Meister GEM from when Nagi is her master is called the Ultimate Black Diamond, and is actually a corrupted form of the founder, Fumi Himeno's GEM, the Pure White Diamond. Her Element is a pair of daggers, or sai, which expands to a large sword. Her Ultimate Element is the Sword of Miroku. In Mai-Otome Zwei, she gets a new Meister GEM, called the Neptune Emerald, and her Element is a bident. Her Element attack is called Dash Cold Water Spout.
(Source: Wikipedia)