One of the most successful and longest-running anime franchises in history, Detective Conan (renamed Case Closed in the U.S.) has been running since 1996, with over 800 episodes and counting. With over 940 chapters published, the manga is the 21st-longest running series of all time.
The hook of Detective Conan is that teenage detective prodigy Shinichi Kudo got a little too close to an illegal drug ring, and got himself dosed with an experimental drug that shrunk him to the size of a seven-year-old. Now he solves cases under the alias Conan Edogawa (after mystery writers Sir Arthur Conan Doyle and Ranpo Edogawa), all while hiding his true identity.
He’s solved a lot of cases over the course of the last 20 years.
Majin Tantei Nougami Neuro
This is one of the more unique premises. Neuro Nougami is a demon who feeds on puzzles and mysteries. So he teams up with human Yuko Katsuragi, who is trying to solve the mystery behind her father’s death. And the two of them solve mysteries – partly to help Yuko, partly to satiate Neuro.
Some demons consume human souls. Apparently some of them just need a Rubik’s Cube.
Danganronpa: The Animation
Let me just start off that if you have a chance to play the Danganronpa visual novel/game, that is the optimal way to experience this story. But if you don’t, it’s a great story worth experiencing one way or another.
It starts with Makoto Naegi gets accepted to a super elite school for super elite students. But he’s just an average guy – he made it in via lottery, which apparently makes him the “ultimate lucky student.”
But as soon as he enters the school, he passes out. When he comes to, there are 14 other kids in the school, no way out, and a largely monochromatic bear named Monokuma who says they’re trapped in the school unless they can commit a murder of one of their classmates and get away with it after an investigation and class trial.
Detective School Q
Detective School is a pretty by-the-numbers detective series. Kyuu Renjo has a knack for logical deduction, and aspires to be a famous detective. Obviously, the best course of action is to enroll in the famous detective school, right?
While there, he teams up with classmates sporting a variety of abilities – photographic memory, martial arts, programming, you name it – to solve an equally wide variety of crimes.
Also, this school has a rule where students are allowed to bear arms. Because detectives have to have guns, right?
Higurashi no Naku Koro ni Kai
It’s important to note, the second season of Higurashi no Naku Koro ni is the one with particularly detective-like themes.
The first season has more to do with just witnessing the creepy, gory details of how a bunch of adorable-but-disturbed kids go crazy and kill each other in increasingly upsetting ways.
The second, Higurashi no Naku Koro ni Kai, is all about getting to the bottom of what’s happening, from the perspective of a character who turns out to be more than she appears to be.