Shin'ichi is a 17-year old student at Teitan High School (Titan High School) and is already a well-known detective. He dreams of being a great detective like Sherlock Holmes and got his dose of reality from his near-girlfriend Ran Mori (Rachel Moore). Shin'ichi's parents, Yusaku and Yukiko (Booker and Vivian) live in the United States while Shin'ichi lives in Japan.

But after witnessing a crime, Shin'ichi is captured and forced to ingest a chemical. The chemical turned him into a young child, and he had to get an alias. His alias is Conan Edogawa (Edogawa Conan), after Arthur Conan Doyle and Edogawa Rampo.

Shin'ichi, as Conan, isn't taken as seriously as a child, so he has to improvise. Shin'ichi frequently knocks out Kogoro Mori (Richard Moore) and uses his voice-changing bow tie to imitate Mori. Because of this, Kogoro Mori gets the credit.

Shin'ichi, as Conan, stays at Ran's house. Knowing that Ran misses Shin'ichi, "Conan" has to call her over the telephone and imitate his original voice so that she isn't worried about Shin'ichi. Only Dr. Agasa knows Conan's true identity.

Conan befriends three other children, Ayumi Yoshida (Amy), Genta Kojima (George), and Mitsuhiko Tsuburaya (Mitch). Together they form the Junior Detective League.