Thanks to significant technological progress, humanity has developed hIEs, human-like robots that serve as public and personal attendants for society. Unlike many others, the kind-hearted high school student Arato Endou treats hIEs as equals, but his financial situation prevents him from ever owning one. However, his ordinary life is shattered when a routine trip to the local grocery store goes horribly wrong. Viciously attacked by a hacked hIE, Arato is on the verge of death; fortunately, he is saved by an abnormal hIE carrying a weaponized coffin. Her name is Lacia, one of five highly advanced hIEs that recently escaped the clutches of the mysterious MemeFrame Corporation. Confronted with a hacked car threatening to run them over, Lacia offers Arato a deal: in exchange for saving his life, he must register as her new owner, thereby taking full responsibility for her actions. With little choice, he decides to trust this artificial girl and allows her to live in his home. Although Lacia begins to adapt to her new, peaceful lifestyle, she warns the entranced Arato of one thing—she does not have a soul.