"Fushigiboshi no Futagohime" is a 2005 Japanese anime television series based on Birthday's concept. The anime series was produced by Nihon Ad Systems under the direction of Junichi Sato and consists of fifty-one episodes. The story follows the adventures of the twin princesses of Wonder Planet (a mysterious planet shaped like a hollow earth). The series was first broadcast on TV Tokyo in Japan between April 2, 2005 and March 25, 2006. A second series, Fushigiboshi no Futagohime Gyu!, immediately followed the first.