Most of the world''s needs are fulfilled by humanoid robots called hIE''s. One day, 17-year-old Arato Endo meets the android Lacia and becomes her owner. She is one of five androids with advanced AI. Each of the five units have their own motivations, and fight to gain each other''s abilities. What will the relationship between man and machine be moving forward? That is something Arato must find.