Gousetsu, also called Master, is the bartender and guild master of the Vampire Hunters' Guild. He transitioned from being an active vampire hunter to managing the guild, handling the receipt and assignment of hunting jobs. He has black hair combed backward, a closed-eye expression, and an English-style mustache. His attire consistently features a bartender's uniform: a white dress shirt, black vest, black bowtie, black waist apron, black pants, and brown shoes.

He generally maintains a calm and friendly demeanor, commanding respect from younger hunters and approaching combat professionally. He is fiercely devoted to his daughter Koyuki, who works as a barmaid at the guild, reacting aggressively to any perceived threats against her. He occasionally indulges in dad jokes, fitting middle-aged character tropes. Gousetsu is happily married, with interactions suggesting affectionate and playful dynamics with his wife. His personal life includes a censored kink publicly revealed by the vampire Ydan Ojisan, though specific details remain undisclosed. He shares a significant, longstanding friendship with the duck-themed hunter Vamone, who uniquely provokes him despite his typically composed nature.