ヴァニラ

The multi-talented head maid of the Alhazred mansion who is in charge of everything related to it. A spirit summoned by Carmilla and bound to a magical ring, she can be likened to a ghost who signed a contract of subservience to the master who summoned her. She always wishes for the happiness of her master, and will do anything to ensure that her master is well cared for and happy. [From the official website]