Humans plan to immigrate to the planet Promete, but President Doppler, who advocates for the chosen people doctrine, insists that only the "superior" can migrate to that planet. Through schemes and tricks, he sabotages the first immigration plan. The astronaut involved in the plan, Dan Hitetsu, is branded a "traitor" and vanishes without a trace. 　　 Ten years later, Dan Hitetsu's son, Takuma, becomes a candidate astronaut for the new immigration plan and undergoes rigorous training under the mysterious masked man, Captain Dan. Meanwhile, President Doppler returns with his henchmen to interfere once again...