Haruka, often referred to as Marquis Haruka or Lord Haruka, is a supporting character in the narrative who holds a significant position within the court of the kingdom of Clarines. He is an older man with a dignified bearing, easily recognized by his slicked-back blond hair and a distinctive goatee. He is almost always dressed in the formal attire befitting his high rank, presenting an image of authority and tradition.

His background is that of a high-ranking noble who has earned the title of Duke through his military accomplishments, a fact he values greatly. Within the palace, his actions and duties suggest he serves as a Master of Ceremonies, making him a key figure in managing courtly affairs and upholding its protocols. He is deeply invested in the kingdom's political landscape and the public perception of its royal family, particularly the second prince, Zen Wistalia.

Haruka's personality is initially defined by a rigid adherence to social hierarchy and a deep concern for the royal family's reputation. He is a dutiful and serious man who believes wholeheartedly that status and birthright are paramount. This makes him deeply suspicious of Shirayuki, a commoner with no title who begins spending time with Prince Zen. He views her presence as a potential threat to Zen's authority, fearing that the people of Clarines will lose respect for the prince if he is seen associating with someone of such low status. His concern for Zen is genuine, but it manifests in a protective and, at first, antagonistic manner toward anyone he perceives as a danger to the prince's image.

This motivation drives his primary role in the early part of the story, where he serves as an initial antagonist for Shirayuki. Convinced that her presence will harm Zen, he takes extreme measures, including hiring the skilled mercenary Obi to drive Shirayuki away from the castle, even against Zen's wishes. However, Haruka possesses a strange and particular sense of justice; he never intended to let Obi take the full blame for the scheme, as he considered it his own decision made for what he thought was the greater good. This moral complexity hints at a deeper character beyond a simple classist villain.

His key relationships are central to his development. His most important dynamic is with Prince Zen, for whom he holds the utmost respect and loyalty. He shows his devotion in a roundabout way, believing he knows what is best for Zen even when it conflicts with the prince's own desires. He also answers directly to the first prince, Izana, with whom he is on good terms, often acting as a reporter on the situations involving Zen and Shirayuki. His most significant and transformative relationship is with Shirayuki herself. They begin as adversaries, but she confronts him directly, proving her resolve and demonstrating that she has her own strength and determination. She does not rely on Zen's status but instead decides to become a court herbalist to enter the castle on her own merits.

This confrontation marks the beginning of Haruka's development. As the story progresses and he witnesses Shirayuki's achievements, her intelligence, and her unwavering commitment to stand by Zen's side without hindering his path, Haruka is forced to change his initial judgment. He does not openly express complete acceptance, but he shows a gentler, more supportive side. He begins to offer her encouragement and pragmatic advice, such as suggesting that if she wishes to declare her position beside the prince, she must do so in a place where people can see her, like moving into the castle's East Wing. This guidance proves he has come to value her as an asset and a worthy companion to Zen.

In terms of abilities, Haruka is not primarily a man of action like the prince's retainers. His power lies in his political authority and his experience within the court. He is a capable administrator and strategist when it comes to courtly matters, but he also demonstrates that he is skilled enough with a sword to draw it and threaten an intruder, though his true strength is his judgement and his shifting perception of people. While the story identifies the official castle physician as an eccentric and talented individual named Garack, Haruka's own abilities are those of a noble lord and trusted, if sometimes misguided, advisor to the throne.