Unknown to the people of Earth, there is a branch of humanity called the "Gosei Angels", whose mission is to protect the Earth. When the Earth is targeted by an evil alien invasion force called Warstar, they destroy Heaven's Tower, the bridge between the Earth and the Gosei World, home of the Gosei Angels, to keep them from interfering. However, five apprentices, Gosei Angels, are on Earth at the time, and while finding a way to return back home, they become the Goseigers to stop Warstar. Soon after, the monstrous Yuumajuu emerges from their slumber, and the Goseigers receive aid from a special being called Gosei Knight, who once fought against the Yuumajuu. But even after they defeat the Yuumajuu, the evil robotic Matrintis Empire rises to take over the Earth with the data acquired from the last two groups. Once they are defeated, the Goseigers face their greatest enemy, the one who has been manipulating the other groups from the very beginning: a rogue Gosei Angel who took their mission to protect the Earth to a dangerous extreme by planning to destroy all life and recreate the world in his image.