The story is set in 2021, 31 years after World War III. Filicia Epstein, a bionics genius, came to Sabano and Sergent Mutou was ordered to protect her. Searching for her only brother, Lyon, Filicia encountered with 1019, a cybernoid, who directed them to the phantom city, OZ, which is a shelter created by Lyon. As the story unfolds, they gradually realised what 'OZ' actually was.