Meitantei Conan (1996)

Shinichi Kudo, a seventeen year old master detective, had it all. He could solve any case brought to his attention and in record time. His girlfriend, Ran, is a karate expert, and her father is a bumbling P.I. who is driven crazy by the fact that Shinichi gets all of the great cases. One day, while Shinichi and Ran are at an amusement park, the pair become separated. Shinichi catches wind of a dirty deal going down, and spies on a pair of men in dark trenchcoats. He's caught and the men use an experimental poison on him, intending to kill him. However, things don't work exactly as planned. When Shinichi comes to, he finds he's shrunken down to the size of a fourth grader. He goes to the goofball inventor that lives next door to him for help, and the inventor agrees to give him a hand. When Ran comes looking for Shinichi, he and the inventor come up with a story saying that Shinichi is a child named Conan Edogawa (Conan as in Sir Arthur Conan Doyle). Ran offers to let "Conan" live with her family while his "family" is away. Shinichi then makes it his mission to one day find the men who poisoned him and get the antidote. Thus concludes the backstory to the series. In each episode, Conan solves a different case in the style of all good detective shows, giving hints to help the viewer try to guess who the villain is, while trying to keep his true identity a secret.