Masaki Kube is a member of the founding family of Macbeth Enterprises, a powerful conglomerate deeply involved with the alien Kill-T-Gang. He becomes the company's chief executive officer after the Kanda Incident, a major scandal involving the illegal genetic modification of children, and the subsequent suicide of the previous CEO. As the head of Macbeth Enterprises, Kube oversees the company's collaboration with the alien forces, including the design of Machine Goodfellow units and the Designer Child program. He is a human executive rather than a combatant, and his role in the story is primarily that of a corporate antagonist who facilitates the Kill-T-Gang's activities on Earth. Kube maintains a close working relationship with his personal secretary, Hitomi, with whom he shares many of his secrets and seems to reciprocate her feelings. Later in the series, his body is taken over by the alien Puck, leaving his ultimate fate uncertain. Masaki Kube is characterized by his position of authority within a morally compromised organization, and his actions are driven by the interests of Macbeth Enterprises rather than personal ideology. He does not possess any supernatural or combat abilities, relying instead on his corporate influence and the resources of his company.