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.

In the great city of Metropolis, severe community structures and prejudice dominate a world where humans and robots live together. Unrest and violence increase with each new day. Searching for the scientist Dr. Laughton, suspected to violate human rights by trading organs, the Japanese detective Shunsaku Ban and his nephew Kenichi arrive at Metropolis. In the scientist's laboratory, Kenichi discovers a girl without any memory of her past life. He decides to help her, so they run away together. His uncle follows him and penetrates the dark secrets of the city to find Duke Red, the man ruling from the shadows. Meanwhile, Kenichi desperately tries to protect the mysterious girl from the people hunting her. However, Duke Red and his adoptive son have their own deep reasons for chasing the girl. These reasons are connected to her true identity and the struggle for the domination of Metropolis...

The true end arc of Ore no Imouto. These four episodes branch out after the 11th episode of the main TV series and present an alternative version to the end of the TV series. These episodes contrast with the good end arc of the TV series, which was an original ending written for the anime, and instead closely follows the original story from the light novels.

Takato Saijou has held the title of "Sexiest Man of the Year" for five years running. He is an accomplished actor, with 20 years of experience under his belt, and is aware his good looks are well above average. Proud of his career, Takato regards the title as an appropriate indicator of his success. But when his reign is ended by acting newbie Junta Azumaya, who debuted only three years ago, Takato's initial shock gives way to jealous hostility. Even in the new drama that he has been cast in, Junta seems to have suddenly surpassed him; snatching Takato's usual spot of lead actor, Junta continually manages to get on his nerves. Most infuriating of all are the bright smile and kind words that accompany everything Junta does. All this animosity comes to a head, however, when Junta catches Takato in a rather vulnerable drunken state. Endangering his own public image, Takato confronts the junior actor with harsh words and angry comments—an opportunity Junta takes every advantage of. With the famous actor Takato Saijou now on video picking a fight with a co-star, Junta has the perfect means to blackmail him. Asking the price of his enemy's silence, Takato is shocked to find that his motivation lies far from advancing his career; instead, Junta's terms are those that can only be realized in the bedroom! [Written by MAL Rewrite]