Case Closed Season 4 Episode 1201

Shinichi Kudou is a child-like high school detective, renowned for solving complex cases. One day, he encounters two unusual detectives on the street. He sets out to track them down and witnesses a dark incident. But his luck runs out and he's caught. The gang then administers a strange, experimental drug designed by their gang to kill him. The boy doesn't die, but when he wakes up in the morning, his entire system has been transformed—he's become a 7-year-old boy! His brain remains as sharp as ever, but he hides this new form from his childhood friend Ran and his fat-headed detective father, Kogorou Mouri, and takes on a new name—Conan Edogawa. Now, this little boy uses his brain to solve all of his fat-headed father's cases on his own, while also secretly trying to track down the gang of thugs so he can grow up again.