Azusa Kasugai is a classmate of Tokiwa and his friends.
One evenig when she was out shopping with a friend after school Azusa became the victim of an azuki-toge. It lured her into a desterted alley with its music where it the attacked her and drained away her spirit to feed on it.
Her friend found her collapsed and she was admitted into hospital. Aria was able to save her life by donating her some of her own energy. Because of Aria's intervention she is the only person out of five to survive an attack by the azuki-toge.