Genre: Horror, Occult detective
Original Name: Majin Tantei Nōgami Neuro
The series’ central character is Neuro Nōgami, a demon who eats mysteries. Because he has eaten every mystery in the demon world, he comes to the human world to feast on the mysteries offered by humans. Because he is a demon, he does not want to make his presence in the human world widely known. He makes an arrangement with a 16-year-old high school girl Yako Katsuragi who wants to solve the mystery of her father’s murder, which was declared a suicide by the police. They establish a detective agency and, together with former criminal Shinobu Godai and a sentient braid of hair called Akane, solve crimes to feed Neuro’s appetite.
The title character of the series, Neuro is a demon detective from hell with a very arrogant, sadistic, and self-centered personality. He came to the Human World to look for the Ultimate Mystery, which is “the most complex, the most unfathomable, and so, the most pleasing to the palate”. Upon arriving to the surface, he met Yako and forced her to become the front that Neuro needed to look for mysteries. While working on cases, Neuro usually makes use of his demonic powers and 777 Tools of the Demon World to find and defeat the culprit.
Yako is a 16-year-old high school girl and the very first character introduced in the manga. She meets Neuro when he appears and desecrates her father’s shrine while promising to help solve the mystery of her father’s death. This meeting quickly leads to a partnership: Yako becomes Neuro’s cover, pretending to be an investigator while Neuro acts as her assistant. Although at first it seems that Yako’s only purpose is to be there as a cover, she later proves herself worthy by being able to decipher the criminal’s motive by using her ability to understand human psychology, something that proves to be useful in certain cases, given how Neuro is unable to understand how humans “operate”.
He is the jack of all trades for the detective’s office and is sometimes referred to as “Neuro’s second slave”. Godai is quick-tempered and yells a lot, but has also been shown to be methodical, responsible, and trustworthy. During the early chapters, Godai worked for a small finance house with criminal connections. However, he was forced to work for Neuro after the latter won the bet for the office by solving their boss’s death. In the manga, he was left to be until Neuro found a use for him, in which the demon then forcibly drags him back to the office, and is currently running an Information Company under Neuro’s supervision.
Akane is a corpse in the wall of the office Neuro took over, who is shown only as a detachable braid of hair, which functions like a hand. Neuro offered to make Yako brush and care for her in exchange for secretarial work. Akane can be taken from the office for short periods of time and can also merge with Yako’s hair to make it longer, which not only gives Akane control over Yako’s natural hair, but if left merged for too long, would make Akane and Yako switch places completely. Akane later appears attached to Yako’s new cell phone.