As part of a school competition, Daisaku, Tetsuya, and Hotaru - three skilled students from a technical high school - develop award-winning robots. However, their victory is overshadowed by the danger looming over the Earth as the malevolent Derinja race seeks to seize control of all space. Faced with this formidable adversary, Professor Mizuki - Hotaru's father - modifies the robots to equip them for battle. Thus, the birth of Albegas, a super robot, takes place.