Yoshitoshi ABe's Haibane Renmei anime manga - Dark Horse

In a long-forgotten walled town, humans coexist with the Haibane, angelic beings of unknown origin. Rakka becomes the newest Haibane after she awakens from a strange dream and finds herself hatching from a massive cocoon. With no memories of her previous life, Rakka struggles to adjust to her new surrounding, however burning questions remain in the back of her mind. What are Haibane and what is their purpose? What lies beyond the town walls? Thus Rakka begins her wistful journey of self-discovery and wonderment.