Anzai is a police detective specializing in investigations involving supernatural cases. He appears alongside Detective Yamazaki during official inquiries, particularly when the protagonist's activities intersect with police work. Following a client's suicide at an S&M club, Anzai participates in interrogating the main character about the death circumstances. Throughout this process, he retains a skeptical stance towards paranormal explanations while rigorously pursuing standard investigative procedures, reflecting conventional law enforcement perspectives on cases with alleged supernatural elements. When presented with the location of a suicide note through unconventional means during interrogation, Anzai acknowledges the evidence and confirms the death as a suicide, demonstrating his adherence to investigative protocols despite the unusual circumstances.