The title character of the series, Neuro is a demon detective from hell. He looks for mysteries in the labyrinthine minds of humans for sustenance. When he dismantles the mystery and strips the culprit of all of their defenses, that 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. Once in the human world, he forced Yako to be his assistant, and began to solve mysteries.    He is a very self-centered, sadistic and arrogant character that cares little about the human aspect of the cases, most of the time only focusing about getting the mystery as quick possible. This can be a disadvantage, however, as he can't relate to or begin to understand the motives of the culprits. He will also commit blackmail and manipulation to achieve his goals. Neuro enjoys abusing and torturing Yako at every chance he gets, and thinks of her as nothing more than a slave to use at the beginning of their 'partnership'. However, recently, there have been a handful of times where he seems to care for her: saving her from injury more than once by explosions, comforting her crudely at the end of the Hal arc, and even stating during his battle with X that seeing her struggling to find her own potential was &quot;very pleasant&quot;. A little before the HAL arc he was constantly telling her to 'evolve' and become more useful to him. From his actions then, it is possible that Neuro expects quite a bit from Yako, expressing disappointment, approval and even pride at certain times.    In public Neuro makes Yako act as the detective, while he acts as her assistant, even though Neuro is actually doing all the detective work. Even though Neuro is a demon, he still needs to sleep but not as long as humans; though the more he is more exhausted, the more he shall sleep. According to Neuro &quot;Shouki is like Oxygen to a demon&quot; and natural hot springs are formed when excess Shouki comes to the surface, so the best place for him to sleep is near a hot spring.    Neuro's true form appears to be some kind of horned bird, often revealed when he is about to feed on the released negative energy. In the manga, unlike the anime, Neuro isn't limited to eating mysteries made by crimes; he has, on at least three occasions, completely disassembled various things to find out how they worked, such as a car, a cellphone, and even a bomb.    As a demon, he shows his inhuman abilities in the early chapters of the series, making him seemingly invincible against human weapons such as catching a bullet with just his eyelashes but as the story progresses, Neuro has received injuries by several criminals. Neuro implies this to X that his body is gradually becoming more like a humans, because of the lack of the Demon's world's Shouki in the human world and that his body is adjusting to the Laws of Physics in the human world. His monstrous endurance remains and ensures his survival longer than what would have killed an ordinary human. Even while his body is weakening, Neuro still was able to easily defeat X in combat.

The Demon Neuro has a raging hunger for 'mysteries.' Being dissatisfied with his current regime in hell, he’s come into the mortal realm in order to satiate his ever-growing appetite. The murder case of a young girl’s father seems to be sufficiently enticing for the Demon’s needs.. But what else might happen between these two? Find out in this disturbingly good murder-mystery series. 
Included one-shot: 
Volume 23: Rikon Choutei (Divorce Conciliation)

The series focuses on Neuro Nougami, a demon who feeds on mysteries and puzzles, who comes to the human world to feast on the mysteries offered by humans who release negative energy from their planned crimes. As a demon, he must not make his presence noticed by the humans as it is the law in the human world. Because of this, he makes a permanent deal with Yako Katsuragi (who has her own personal mystery she has to solve), and together they solve crimes for Neuro's appetite.

[Blog](http://koyap.jugem.jp/) | [Agency Profile](https://tsf-official.com/talent/takehito-koyasu/)

Koyasu is the most prolific voice actor in the industry, having been credited for over 700 roles as of April 2022.

Growing up, Koyasu skipped out on going to school to watch movies at home because he wanted to become an actor. It wasn’t until later that he became interested in voice acting after having seen [Galaxy Express 999](https://anilist.co/anime/1491/). After graduation he entered a voice acting school. In 1988, he made his voice acting debut, and got his first regular role a year later voicing [Gai](https://anilist.co/character/13374/) in [Tenkuu Senki Shurato](https://anilist.co/anime/2113/).

Though having voiced more characters in the medium than anyone else, he is probably most known for his role as [Dio Brando](https://anilist.co/character/4004/) in [JoJo’s Bizarre Adventure](https://anilist.co/anime/14719/). He has stated that he likes playing villainous characters.

Koyasu has taken over many of [Kaneto Shiozawa](https://anilist.co/staff/95424/)’s roles after Shiozawa’s passing.

Father of [Kouki Koyasu](https://anilist.co/staff/219102/).

__Non-Anime Roles:__

- Olivert Reise Arnor - The Legend of Heroes Series (VG)
- More - Metaphor: ReFantazio (VG)
- Mustang - Goddess of Victory: Nikke (VG)