Digimon Frontier (Japanese: デジモンフロンティア, Hepburn: Dejimon Furontia), known as Digimon: Digital Monsters (Season 4) in English-speaking territories, is the fourth anime television series of the Digimon franchise, produced by Toei Animation. Unlike the first three series, the main characters, the DigiDestined merge with ancient spirits known as "Legendary Warriors" to become Digimon themselves, instead of training. Like Digimon Tamers, the climax features any human fusing each partner as a Mega form. The series aired in Japan from April 7, 2002 to March 30, 2003, with an English-language version, produced by Sensation Animation, airing in North America from September 9, 2002 to July 14, 2003. It was the last season to use the Digital Monsters title as subsequent series, beginning with Digimon Data Squad and using unique localized titles.