Detective Conan: Episode "One" - The Great Detective Turned Small

It all started when Ran Mori lost her smartphone. Shinichi Kudo, her would-be boyfriend, promises to replace it, but the high schooler is already making his name as a consulting detective for the police; when he abruptly leaves her karate tournament to skillfully solve a high-society murder case, Shinichi's going to have a take Ran on a special date to get back on her good side. A colorful amusement park beckons-- and so does a horrifying act of homicide! In pursuing this new murder mystery, Shinichi stumbles across the shadowy Black Organization, a crime syndicate that attempts to silence the gifted sleuth the only way they can without attracting attention-- by force-feeding him a strange drug with unknown properties. Now, Shinichi finds himself younger--so much younger, in fact, that his police allies don't even recognize him! Armed with nothing but his wits and a brand new identity as Conan Edogawa, boy detective, Kudo takes off in pursuit of justice, answers, and someday, a return to his original age.