Kō Mukuroji is a mysterious and enigmatic figure at the heart of the horror anthology series Nanashi Kaidan. He first appears as a boy with short black hair and red eyes, but he also appears in an adult form, suggesting a nature that transcends age. In his public life, he works as a concierge at a department store, where his elegant, gentle, and warm tone of voice has made him immensely popular with customers. Despite this friendly and professional persona, there are persistent rumors that he harbors a secret identity as a storyteller of forbidden ghost tales. He rarely indulges this side during work hours, but occasionally whispers to intrigued customers to return after closing time for a private narration. His love for ghost stories is a defining trait, and his personal motivations remain largely ambiguous. As the series progresses, he is seen using a fox spirit to attack the two child protagonists, Bon and Koko, though the purpose behind this aggression is never fully explained. His role in the story is that of a mysterious catalyst: his narrations seem to summon or release supernatural entities that Bon and Koko must then seal away. He does not appear to have clear allies, and his relationship with the main pair is one of enigmatic opposition, perhaps testing their abilities. Kō Mukuroji undergoes little visible personal change over the course of the series, keeping his origins, true intentions, and ultimate nature shrouded in mystery. His notable abilities include commanding a fox spirit, possessing deep knowledge of supernatural lore, and apparently bringing his stories to life in the real world.