Fleeing from his own race, Orgun—an alien being with superhuman abilities and unearthly weapons—travels to Earth to find an answer to his origin. There, he bonds with a young man named Tomoru to defend Earth against the Evoluders, who seek nothing but destruction of other civilizations.

Fleeing from his own race, Orgun—an alien being with superhuman abilities and unearthly weapons—travels to Earth to find an answer to his origin. There, he bonds with a young man named Tomoru to defend Earth against the Evoluders, who seek nothing but destruction of other civilizations.