Noé Archiviste is a 19-year-old vampire who stands out visually with his dark skin, fluffy short white hair, and striking purple eyes that flare crimson when his vampire instincts take over. Tall and well-built, he typically dresses in elegant, light-colored Victorian attire chosen by others due to his own total lack of interest in fashion. Personality-wise, Noé is deeply empathetic, polite, and fiercely loyal, balancing a childlike naivety and an intense love for sweets with immense superhuman strength and a sharp combat instinct. Despite a traumatic past, he remains an endlessly hopeful idealist who genuinely seeks to understand and protect both humans and vampires alike.

Vanitas is an enigmatic 18-year-old human doctor with shoulder-length, messy dark blue hair, vibrant blue eyes, and a striking hourglass-shaped earring. He typically wears a dark, elaborate Victorian-era coat, a white shirt with long cuffed sleeves at the elbows, and dark blue vest with a light blue bow attached, black pants, and black gloves that hide the blue, glowing crescent moon insignia marking him as an inheritor of the Vampire of the Blue Moon's power. His personality is a complex shield of arrogance, theatrical flamboyance, and cynical pragmatism, which he uses to mask a deeply fragile, self-loathing psyche and a traumatic childhood. Despite his sharp tongue and insistence that he is only acting out of spite, he possesses a brilliant mind and a fierce determination to cure vampires of their malady using the legendary, "Book of Vanitas."