Neuro Nougami is the titular character of the series and the main protagonist. Neuro is the arrogant, sadistic and self-centered demon detective from hell. He came to the human world in search of the so-called “Ultimate Mystery” which is so complex, and unnervingly unfathomable that it would be most pleasing to his rather unique palate. He feeds his limitless appetite with mysteries of a person’s mind when acting upon their well-planned crimes. He uses his demonic abilities and the 777 tools of the Demon World to solve mysteries and eventually defeating the culprits.