Hatsuka Suzushiro is a supporting character in this anime, a vampire whose most immediately recognizable trait is his strikingly androgynous appearance. He has a slender build, long black hair often styled with blunt bangs, and typically wears feminine clothing such as long-sleeved striped dresses, coats, and calf-length boots. Despite this presentation, Hatsuka identifies as a man and uses the masculine first-person pronoun "boku". He chooses to dress this way simply because he feels it suits him, and he is confident and unapologetic about his gender expression.

In terms of personality, Hatsuka comes across as calm, laid-back, and more emotionally distant than many of his fellow vampires. He is observant and perceptive, often able to predict what others are going to say. He is less confrontational than other vampires, notably refraining from attacking the protagonist Kou Yamori upon their first meeting. However, this relaxed demeanor masks a more manipulative and authoritative nature. He holds a cynical view of love, believing it to be a form of brainwashing, and he has no qualms about using this philosophy to control others. This is most evident in his treatment of his three human servants, two women and one man, whom he deliberately conditioned into a state of deep psychological dependence before turning them into vampires. In his own home, he enforces strict rules, such as forbidding them from speaking without permission or using the living room sofa, which is reserved for himself and guests.

Hatsuka's motivations are often self-serving, centered on his own amusement and comfort. He shows little interest in the typical vampire goal of creating a large number of offspring, preferring to maintain a small, intensely loyal household. He is also genuinely invested in the romantic dynamics between others, showing unexpected enthusiasm, particularly when Nazuna Nanakusa asks him for advice on how to make Kou fall in love with her. His interest in Kou is primarily due to the reported delicious taste of his blood, and at one point, he offers to turn Kou into his own servant to protect him from other vampires, intending to use his powers to brainwash the boy.

Within the story, Hatsuka serves as a unique confidant and advisor. He is one of the few characters to call Nazuna by her last name, "Nanakusa-san," and she, in turn, visits him to discuss her complicated feelings for Kou. He plays a key supportive role by sheltering Kou when he is being chased by the vampire hunter Anko Uguisu and later by offering him a place to hide from the police. He acts as a mediator of sorts, arranging meetings among the vampires to discuss threats like Kiku Hoshimi and assisting in stopping Anko's attacks. His key relationships include his acquaintance with Nazuna, his tense dynamic with the more aggressive Nico Hirata, and his calculated, master-servant relationship with his three familiars.

In terms of development, Hatsuka's character is revealed slowly, most notably in the story arc where his true gender is disclosed to both the protagonist and the audience. A brief flashback to a person in a female school uniform hints that his own past experiences may have shaped his current identity and beliefs. Despite these glimpses, much of his long history as a vampire remains unexplored.

As a vampire, Hatsuka possesses the standard abilities of his kind. These include immortality, superhuman strength, speed, and durability, the power to levitate and phase through solid objects, accelerated regeneration, and a supernatural charm that makes him alluring to humans. His name, Suzushiro, is an old term for the daikon radish and is also one of the seven herbs of spring, tying into a thematic naming convention used in the series.