Hirawa Hirito, his own son. Unlike him, Hirito shows a rather cheerful demeanor―just like his mother. Ever since Naoya brought him to the Yoichi estate, Hirito spent a lot of time with the other butler and maids there, even with the young lady of the estate. Though, for most of the time, Hirito spent his time at a daycare instead. Despite the minimum time he spent with Hirito as a father, he loves him all the same. Naoya's way of showing love is a bit different, some might say. Perhaps, due to his moniker as a robot.

Yoichi Seina, his young lady. In total, he devoted his life to her for 14 years, and still counting. Just as how he had put it, he considered himself as her father, her mother, her brother, her everything. It brought his protective sense to the max. Sometimes, he even annoyed his young lady because of his desire to keep her happy, safe, and sound. At this point, he came to believe that his purpose was to be her everything―the masterpiece of his work as a butler. His young lady's personality is almost the exact opposite of his, so along his devotion to her, he slowly learn something new. Both about him, and her. It's just as how his late father had told him; slow and steady is the best approach for everything. Who knows what'll become of them, after their slow and steady steps together.