Natsuki Kruger

ナツキ・クルーガ, Ice Silver Crystal
The headmaster of the Otome academy she was schoolmates with Shizuru Haruka and Mai. She is 2 of the Five Columns and is known as the Ice Silver Crystal. She is from the remote region of Count Krugers territory. It is strongly implied that she and Shizuru are lovers. During her days as a student she and Mai were rivals. She was Shizurus room attendant and later Rosalies Florences Otome oneesama. Her Element is a massive energy cannon capable of executing an attack called Howling Silver Wolf. Source: Wikipedia