Nougami Neuro (from Wikipedia)
Seiyuu: Takeito Koyasu
The title character of the series, Neuro is literally a detective from Hell (Makai). He looks for mysteries and the labyrinthine mind for sustenance. As he explains it, 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 Makai were bland and repetitive. Once in the human world, he adopted Yako as his assistant, and began to solve mysteries. He does this because there's a rule in Makai that when the Makai inhabitants go to the human world, they must keep a low profile. 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 (though Yako occasionally figures things out herself as well). In the human world Neuro needs to sleep for three hours a day, which he spends on the ceiling. According to Neuro "Shouki is like Oxygen to a demon" and hot springs are formed when excess Shouki comes to the surface, so the best place for him to sleep is a hot spring. As Yako points out, he comes to the human world because eating is more important to him than oxygen.
Katsuragi Yako (Thanks to Tidah of the Majin Tantei Nougami Neuro LJ Community)
Katsuragi Yako is the very first character introduced in the series. She meets Neuro when he shows up, desecrates her father's shrine, and promises to help solve the mystery. She is absolutely terrified of Neuro at first, since he has a lot of sharp teeth and drools everywhere, but lately she's gotten comfortable enough to ask questions (and ask him for help on her homework, but that was more trouble than it was worth in the end, especially when Neuro made her teacher's brain turn into mush instead of doing her homework). She is often surprised by the turn of events. In the Aya Asia story, Yako shows surprising depth when Aya demands to hear the verdict from her own mouth.
Yako also has connections with the police: Sasaduka Eishi, a previously junior officer who worked on her father's case, feels guilty about what occured and often allows her and Neuro onto crime scenes, helping out when things get physical. He also gets Yako food on occasion.
She also dislikes her new 'reputation' thanks to Neuro flinging her onto the stage when TV cameras were rolling during the Aya Asia arc. She even has a sweaty fanboy asking her to sign his shirt.
I choose to do a fanlisting for Yako and Neuro because I think that they are a great duo, even if he treats her so badly! XD
I think that they would be really cute together, I hope that at the end it would be so... But friendship is not bad after all! ^_^" They have two different kind of characters, and they could be attracted by each other for this, who knows! *-*