Princess Ángela is a princess of the undersea kingdom. Her primary mission is to oppose the conquest plans of King Magma VII, ruler of the underground world, to prevent the destruction of her home and other worlds. This mission forges an alliance with a young boy named Isamu. Together, they undertake a journey astride a fire dragon and receive assistance from their loyal companions, Tail and Octopus, in their efforts to stop the antagonist.