In the English version of Case Closed, Jimmy thinks with his adult voice, Jerry Jewell while he is Conan. However in the Japanese version of Detective Conan, Shinichi thinks with just a more relaxed and matured tone of his young Conan voice, Minami Takayama.
The title Detective Conan was changed to Case Closed in the U.S. due to trademark issues on the name "Conan".
A lot of the names of the main and secondary characters were changed for the English speaking countries. This includes Shinichi Kudo-Jimmy Kudo, Ran Mouri-Rachel Moore, Professor Hiroshi Agasa-Doctor Herschel Agasa, Ayumi Yoshida-Amy Yaeger, Mitsuhiko Tsuburaya-Mitch Tennison, Genta Kojima-George Kaminski, Inspector Juzo Megure-Inspector Joseph Meguire, Detective Wataru Takagi-Detective Takagi Wilder, Inspector Ninzaburo Shiratori-Inspector Santos, Commander Kiyonaga Matsumoto-Commander Kristopher McLaughlin, Detective Sango Yokomizo-Detective Worthington, Cheif Heizo Hattori-Cheif Martin Hartwell, Sonoko Suzuki-Serena Sebastian, Heiji Hattori-Harley Hartwell, Yusaku Kudo-Booker Kudo, Yukiko Kudo-Vivian Kudo, Eri Kisaki-Eva Kaden, & Kaitou Kid-Phantom Thief Kid.