Yako Katsuragi is an acclaimed high school detective, who, despite her young age, has solved many cases. In fact, there seems to be no case that she can't solve, or any culprit that escapes justice. But within the walls of her detective agency lies the secret to her prolific crime-solving skills: the cases are actually solved by her assistant, Neuro Nougami. However, to call Neuro an ordinary man would be incorrect. In reality, he is a demon, who came to the human world in search of the ultimate mystery, having already solved every mystery in the demon world. With Yako as his proxy, he feasts on the negative energy released by humans when they commit crimes. Thus, he promises to help Yako solve the mystery of her father's death. But to do so, he must avoid drawing too much attention to himself, which is why Yako plays the role of the detective. Majin Tantei Nougami Neuro follows this unlikely duo as they solve case after case to satisfy Neuro's ravenous appetite and Yako's desperate search for the truth of her father's death.

Ura Ex, extra short anime included in Blu-ray and the DVD releases of Ao no Exorcist.

Disillusioned with the afterlife, a new student causes a scene during a classroom test and expresses his doubts about whether getting good grades can really lead to escaping the school and ascending to Heaven. Afterwards, he is confronted by the new student council president—a familiar face whose past experiences give him powerful insight into the true nature of the school and first-hand knowledge regarding the futility of rebellion. [Written by MAL Rewrite]

As the Shinda Sekai Sensen (SSS) continue their vindictive rebellion against God, their leader, Yuri Nakamura, comes up with an ingenious plan to escape the afterlife. Her subordinates prepare to carry out "Operation High Tension Syndrome" to deceive Kanade Tachibana, student council president and alleged associate of God, into thinking that they are ready to pass on. With a week's worth of food on the line and with Heaven as the ultimate prize, will the SSS members be able to fool the inscrutable Kanade? [Written by MAL Rewrite]