The alien giant that devoured the stars came out of the sky, and the fate of the earth was in jeopardy. Humans are forced to live underground. Humans who are unwilling to survive like ants have spent twenty years creating the ultimate weapon against giants. But before the day of the decisive battle, the giant noticed the crisis in advance, the human underground civilisation was destroyed, and the only chance to fight back, at this time, was in the hands of a boy who hated humans. Can he let go of his hatred and save humanity?