Digimon Frontier (デジモンフロンティア, Dejimon Furontia), known outside of Japan as the fourth season of Digimon: Digital Monsters, is the fourth television anime series produced by Toei Animation based on the Digimon franchise. The series is noticeably different from other seasons as the main characters, the Digidestined, don't train Digimon to fight for them but instead merge with ancient spirits (known as 'Legendary Warriors') to become Digimon themselves.