Name Mari Evans Age / Height Official data unreleased Gender Female Status / Occupation Former genius martial artist / Maid / Student Current Role Arthur's exclusive 'Robot Maid' and bodyguard. She is actually human but is hiding her true identity. Appearance She has pink hair. Personality She rarely shows facial expressions and does not display her emotions outwardly. On the surface, she seems cold and mechanical, but in reality, she is highly responsible and warm-hearted. She gradually becomes aware of her own feelings while spending time with Arthur. Abilities A former martial artist with genius-level combat skills. She possesses enough fighting power to face assassins directly. Thanks to her expressionless personality, she is very skilled at acting like a real robot. Background Recruited by Roy to work as a robot maid at Arthur's mansion. Since Arthur hates humans and refuses to keep them near him, Mari thoroughly hides the fact that she is human. In a dangerous situation where she could be executed if her identity is discovered, she protects Arthur from assassins. School Life She attends the same school as Arthur. She leads a double life as a regular student while maintaining her role as a maid and bodyguard. When Noah transfers to the school to target Arthur, the three of them end up crossing paths. At school, she wears a uniform and guards Arthur while pretending to be a student. She claims to be in 'Human Mode' at school, but because she remains expressionless like a robot, the other students don't pay much attention to her. Relationship with Arthur Initially, they were just a protectee and an employee, but she gradually develops feelings for him as they live together. Her biggest conflict is that she cannot tell him the truth because Arthur believes she is a 'robot.'

Arthur Louis Zetes Name Arthur Louis Zetes Age / Height Official data unreleased Gender Male Status Heir to the massive Zetes conglomerate Personality Outwardly cold and picky, he harbors an extreme hatred for humans. He especially loathes humans who lie. However, he shows a completely different side to Mari, whom he believes to be a real robot. In front of Mari, he reveals an innocent and spoiled side, caring for her excessively. Appearance Golden hair. Background Having suffered from succession competitions and assassination threats within the family since childhood, he has developed a deep distrust of humans. Because of this, he rejects relationships with people, but he trusts Mari and Roy, believing Mari to be a robot. School Life He attends the same school as Mari and is active in the student council. He is famous at school as a chaebol heir and even has a fan club that admires him. Relationship with Mari Believing Mari to be a real robot, he harbors deep affection for her. It is an ironic relationship where he trusts her the most without knowing she is human. He shows jealousy and wariness whenever Noah approaches Mari.

Maynard Name Maynard Louis Zetes Age / Height Official data unreleased Gender Male Status Arthur's half-brother / Rival for the Zetes family succession Personality He resents the highly capable Arthur and competes for the position of successor. Rather than taking action himself, he is the type to hire assassins to eliminate Arthur. Appearance Hair that is a slightly deeper shade of gold than Arthur's. Goal To eliminate Arthur from the succession race and secure a dominant position for himself. Abilities / Means He utilizes power and organizational strength rather than direct combat. He repeatedly targets Arthur's life by hiring assassins like Noah. Relationship with Noah Noah's employer. He uses Noah as an assassin to get rid of Arthur.

Noah Name Noah Age / Height Official data unreleased Gender Male Occupation Assassin Employer Maynard Target Assassination of Arthur. Personality Unlike a typical assassin, he has a considerably dangerous and crazed side. He displays a playful and mocking attitude, but beneath that lies a strong obsession and sense of danger. Appearance Black hair. Abilities A skilled fighter with combat prowess great enough to push Mari to her limits. He clashes with Mari several times in his attempts to assassinate Arthur. Relationship with Mari Initially, he fought Mari to kill Arthur, but through their repeated clashes, he becomes interested in Mari herself. Afterward, he becomes a rival who targets Arthur while showing a strong interest in Mari. School Life He enters the school Arthur and Mari attend as a transfer student. This puts the assassin, the target, and the person he has become interested in all in the same space.

Name Roy Gender Male Occupation Arthur's butler Role A capable butler who has served the Zetes family and Arthur for a long time. He is cold, calm, and not easily shaken by any situation. He was involved in hiring Mari and setting up the robot maid disguise, and he manages the order of the mansion while protecting Arthur. Though strict on the outside, he sincerely cares for Mari and Arthur. Personality Prudent, highly responsible, and deeply loyal. He is firm when necessary but looks after the two of them with great care. Appearance Black hair. Features He prioritizes Arthur's safety above all else and is one of the few people who knows Mari's secret.