The game introduces the star system of Algo, and its three planets Palma, Motavia and Dezoris. The system is in the grip of its evil ruler, King Lassic. A young girl, Alis, sees her brother die whilst trying to investigate King Lassic, and swears to avenge his death by ridding the system of the evil influence of Lassic.

Alis is soon joined on her quest by Myau - a cat-like creature, Odin - a legendary fighter, and Noah, an Esper. Together they explore the planets of Algo, gathering mystical weapons and armour, battling with Lassic in his castle in the sky, and finally discovering the hidden darkness behind it all.