Detective Conan OVA 3: Conan and Heiji and the Vanished Boy

Synopsis:

Ran and Conan have been invited to visit Osaka by Heiji and Kazuha. Once there, they run across three children - Mayumi, Mikihiko, and Kenta - who have an uncanny resemblance to Ayumi, Mitsuhiko, and Genta. The trio is searching for their friend Satoshi who has gone missing, and they want Heiji's help to find him. Soon, our detectives discover that Satoshi's disappearance may have something to do with a bank robbery that happened earlier in the day. It's a race against the clock to save Satoshi before it's too late!