Digimon Frontier (Japanese: デジモンフロンティア, Hepburn: Dejimon Furontia), is the fourth anime television series in the Digimon franchise, produced by Toei Animation. Unlike the previous series, the main characters are able to merge with ancient spirits known as "Legendary Warriors" to become Digimon themselves. The series aired in Japan from April 7, 2002 to March 30, 2003. An English-language version, produced by Sensation Animation, was broadcast in North America from September 9, 2002 to July 14, 2003 as the fourth season of Digimon: Digital Monsters.