Mai-Mai Miracle

Ten years after the end of the Second World War, in a backwater rural town which used to be a major regional capital in Feudal Japan, Shinko, a girl with an active imagination who daydreams about the town as it appeared a millennium prior, befriends Kiiko, a shy girl from Tokyo whose father relocated to the town to become a doctor for a factory. The film follows their day to day lives as they take care of a goldfish in a makeshift pond, fantasize about a cloistered and lonely young princess who moved to the town in the Feudal Era, and help a boy cope with a family tragedy.

Synopsis from Anime News Network