Demon detective from hell. He looks for mysteries in the minds of humans for sustenance. When he dismantles the mystery and strips the culprit of all of their defenses, it releases the negative energies that caused the culprit to commit the crime, which he then consumes. He came to the human world in search of the Ultimate Mystery, as all of the mysteries in hell were bland and repetitive. In public Neuro makes Yako act as the detective, while he acts as her assistant.