Detective Conan S00 E03 Conan, Heiji, and the Vanished Boy

"One truth prevails."

Conan and Ran are visiting Heiji and Kazuha in Osaka but while they are touring around they come across a group of three kids that look like Ayumi, Mitsuhiko, and Genta. The group are looking for their missing friend and Conan agrees to help.