Matchless Raijin-Oh (絶対無敵ライジンオー, Zettai Muteki Raijin-Oh; lit. Absolutely Invincible Raijin-Oh) is a 51 episode Japanese anime television series, and the first generation Eldran franchise funded by Tomy and produced by Sunrise. It aired in Japan from April 3, 1991 to March 25, 1992 and later be succeeded by the second generation of the Eldran series Genki Bakuhatsu Ganbaruger. The story revolves around a group of elementary school children who are given command of a mecha named Raijin-Oh and their efforts to defend the Earth from the evil Jaaku (evil) Empire. There is also a four-episode OVA sequel.