Yamibo - Season 1

The story follows the travels of Hazuki Azuma, a tall, brooding high-school girl, as she searches for her adopted older sister, Hatsumi. After the disappearance of her sister, a talking parakeet nicknamed Ken-chan introduces Hazuki to Lilith, the caretaker of the Great Library and the many different "book worlds." Each book in the library contains a different world, and the guardian of the library takes on the title Yami. It is within these book worlds that Hazuki must search for Hatsumi.