Hatsuka Suzuhiro is a vampire who moves through the world with an air of mystery and deliberate ambiguity. At first glance, his long hair, slender build, and preference for stylish dresses and feminine clothing often lead others to mistake him for a woman. However, Hatsuka is male, a fact he does not hide but simply does not find necessary to announce. He chooses to dress as he does because it suits him, not out of any discomfort with his gender, and he is fully aware that his androgynous charm attracts the attention and admiration of both men and women.

Before becoming a creature of the night, Hatsuka was human, and this history gives him a unique perspective on his immortal life. In his current existence, he maintains a household of three familiars, one male and two female, all of whom are vampires who are emotionally and psychologically dependent on him. This dependency was created intentionally; Hatsuka fostered deep emotional bonds with them before turning them, ensuring their loyalty and making it impossible for them to imagine life without him. This calculated approach to creating his underlings reveals a strategic and controlling side beneath his elegant surface.

Personality-wise, Hatsuka is a study in contrasts. He is friendly, charming, and maintains a composed, elegant demeanor that puts others at ease. He speaks politely, referring to Nazuna Nanakusa by her last name, Ms. Nanakusa, a gesture that signifies both respect and a certain distance. While he can be flirtatious and teasing, he is also a sharp-witted and emotionally intelligent individual who often acts as a voice of reason among the more volatile members of his vampire circle. He is genuinely interested in emotional connections and, unlike some of his kin, he does not enjoy meaningless killing, suggesting a moral code that prioritizes consent and emotional readiness over predatory instinct. This maturity makes him a reliable source of perspective.

In the story, Hatsuka serves as a key supportive figure for the protagonist, Kou Yamori. When Kou is in trouble, such as when he is fleeing the vampire hunter Anko Uguisu, Hatsuka offers him shelter and guidance. He provides Kou with a place to think and offers insights into the nature of vampires, admitting that even vampires themselves do not fully understand their own kind. When Kou is confused about his feelings for Nazuna, Hatsuka offers thoughtful, grounded advice on love and transformation. He also acts as a confidant for Nazuna, who seeks him out to discuss her complicated relationship with Kou. In moments of conflict, he has proven capable of defending himself and others, assisting a fellow vampire to stop an attack by breaking a weapon.

His key relationships are defined by emotional depth and control. His bond with Nazuna is one of mutual respect and understanding; she trusts him enough to ask for his advice, and he supports her from a distance, hoping she will confront her true feelings. With Kou, Hatsuka is a mentor and a calm, non-judgmental adult figure. He teases the boy but genuinely respects his sincere desire to fall in love on his own terms, even going so far as to offer to glamour him to save his life, an offer he makes without any apparent malice. His most complex relationship is with his three familiars, where he maintains a position of absolute, calculated dependence.

Hatsuka undergoes subtle but meaningful development. Initially appearing as just another eccentric vampire in the background, he gradually reveals himself to be one of the most emotionally perceptive and grounded characters. He moves from a mysterious figure to a trusted confidant for both Kou and Nazuna, playing an active role in helping them navigate their shared journey toward understanding love. His perspective challenges the expectations of both humans and vampires, reinforcing the series' central theme that genuine connection defies simple labels and cannot be forced.

Hatsuka does not possess combat-oriented superpowers beyond those common to his species, such as superhuman strength and the ability to create thralls or familiars. His most notable abilities are social and psychological. His primary power is his immense personal charisma, which he wields with surgical precision to disarm and attract people regardless of their gender. He is also highly skilled at creating deep emotional dependency, a talent he has used to build his own devoted retinue of followers. His true strength lies not in physical might, but in his intelligence, patience, and deep understanding of the human heart.