Ubi was a rabbit that was the pet of the young Isawa Kaede. One of the most powerful lessons in young Kaede's life was the death of her pet rabbit. As a small child, Kaede cared for the rabbit as a close friend. Unfortunately, one day she decided to help Ubi cool off by letting him "feel the brook water." Kaede opened the rabbit's mind to the Void, overwhelming the small animal and killing it instantly. Isawa Ujina consoled his daughter, telling her that the knowledge of the Void is not for others to share, and that she must learn to be strong, as her gifts would force her to be alone for most of her life.