Aria Aria is one of the twelve sister characters in the anime and light novel series Sister Princess. She is the eleventh sister and is known for her gentle, soft-spoken, and dreamy personality. Aria often appears sleepy and is rarely seen without her beloved stuffed bear. Her character embodies innocence and tranquility, providing a calming presence among her more energetic siblings. In the series, Aria's role is to bring a sense of peace and comfort to the group, often acting as a soothing influence.