[Taken from the Tezuka Osamu website:]

Based on "Unico and the Kingdom of the Sun," which was newly written as a theater version, this animated film features a battle between the wizard Kukuruku and Unico. Kukuruku builds a castle using dolls transformed from men as building parts. The story revolves around the sorrow and terror of men who have been transfigured into dolls, and a girl named Cherry who wishes to recover the kindness in her brother, who is a student of Kukuruku. This work reminds us of the fact that "transformation" or "transfiguration" --- favorite themes of Tezuka Osamu --- involves not only material aspects, but also man`s immaterial heart.