TV-Series
Description
Arthur Louis Zetes is the heir to the powerful Zetes conglomerate and the male protagonist of the story. He is a young man who has become deeply misanthropic due to the circumstances of his life. As the illegitimate son of the former family head, he is constantly in danger from assassins sent by jealous relatives, most notably his stepbrother Maynard, who resents his existence and his position as heir. This constant threat has led Arthur to despise humanity, as he believes everyone who approaches him does so with ulterior motives, often driven by greed or a desire to see him harmed. His solution to this problem is to place his trust only in emotionless objects, which leads him to demand a robot maid who can serve him without the deceit he associates with people.

Arthur's personality is defined by a stark contrast between his public persona and his private self. In public, he is often blunt, no-nonsense, and appears as a virtuous if somewhat cold, heir. He has a packed schedule and has accepted a life of constant danger as a normal consequence of his status. However, behind closed doors, his mask comes off, and he reveals himself to be an emotionally needy and somewhat vulnerable individual. He is surprisingly gullible, readily accepting even the most outlandish explanations from Marie, such as her claim that she runs on AA batteries or has a built-in forehead thermometer. This gullibility is a source of humor but also highlights his deep-seated desire to believe in the fiction of Marie's mechanical nature because it provides a safe, uncomplicated relationship. He can be a doting and caring master to his robot maid, showing her a level of consideration and affection he denies to humans. For instance, he becomes an enthusiastic robot otaku, showering Marie with gifts and attention.

Arthur's primary motivation is survival and the maintenance of his position, but on a deeper level, he craves genuine connection without the fear of betrayal. His role in the story is that of the protected master. He is the target of numerous assassination attempts, which serve as the catalyst for Marie to demonstrate her fighting abilities and for their relationship to develop. He is also the unknowing object of Marie's affections and the one she must deceive to keep her job. As the story progresses, Arthur begins to see Marie not just as a machine but as a safe haven where he can finally let his guard down at the end of the day. He shows a willingness to protect her dignity and becomes possessive of her, demonstrating that his feelings for her are deepening beyond that of a master for his property.

Key relationships define his world. His most significant relationship is with Marie, the human maid he believes to be a robot. She is the only one with whom he can show his vulnerable side, and he has come to rely on her completely, even as he remains oblivious to her true nature. His stepbrother Maynard is his primary antagonist, the source of most of the assassins who plague him. Noah is another antagonist, an assassin who knows Marie's secret and uses it to torment both her and Arthur. His butler, Roy, is a paternal figure who orchestrates the deception with Marie for Arthur's own good, while his aunt Charlotte and uncle Carl are among the few relatives who genuinely support him. A painful past relationship also exists with a former friend named Daryl, whose betrayal in childhood left deep emotional scars and reinforced Arthur's distrust of others.

Throughout the story, Arthur undergoes significant development. He starts as a confirmed misanthrope who sees no value in human relationships. Through his interactions with Marie, he slowly begins to open up, showing more emotion and even jealousy. His growing feelings for his "robot" maid force him to confront his own prejudices and his need for connection. An episode where he recounts his childhood trauma of being bullied and betrayed by a close friend shows how deeply he has been hurt, and his growing trust in Marie represents a major step in his emotional healing. By playing his abandoned piano again at the end of that episode, he shows he is gradually becoming a happier and more whole person, in no small part due to Marie's unwavering, if deceptive, presence in his life.

As the heir to a massive fortune, Arthur possesses no superhuman or notable combat abilities of his own. His wealth and status are his primary resources, which allow him to hire bodyguards like Marie and leverage his family's influence. His most notable personal ability is perhaps his unexpected resilience and a cunning streak, as shown when he secretly records his own kidnapping to use as blackmail against Maynard. However, his primary function in the narrative is not as a fighter but as the emotional core whose need for love and trust drives the plot forward, with Marie serving as his shield and, eventually, the key to his happiness.