Detective conan
From Animepedia
Case Closed
Case Closed or Detective Conan is about a boy named Jimmy Kudo who becomes a famous detective at a young age but one day while at a carnival with his childhood friend Rachel Moore is slipped poison that turns him back into a kid. to hide the fact that he is still alive from the men who poisoned him he creats a new identity and becomes Conan Edogawa. to keep him and his loved ones safe Jimmy tells no one about what happen but to a dear friend of the Kudo family Dr Hiroshi Agasa who is a inverter. Conan(aka Jimmy) ends up living with his childhood friend Rachel and her dad Richard who is a detective and as he helps Richard solve mysteries he stays on the look out for any clues about the men who poisoned him.
more information: http://www.detectiveconanworld.com