Mikihiko Yagi

Mikihiko is portrayed as an ordinary child worried about a friend who has disappeared. He cooperates with Conan and Heiji rather than trying to investigate the dangerous situation independently.

Because his appearance is limited to the OVA, the story does not establish an extensive personality or independent character arc for him.

Mikihiko has no special abilities or formal investigative training.

His value to the investigation comes from firsthand knowledge of Satoshi and the children's shared environment. Details remembered by Satoshi's friends provide Conan and Heiji with information unavailable through conventional police questioning alone.

Mikihiko appears when Conan and Heiji investigate Satoshi's disappearance in Osaka. He, Mayumi, and Kenta help establish who Satoshi is and provide background necessary to understand the missing boy's clues.

The three children function as witnesses and friends rather than detectives, leaving Conan and Heiji to determine what happened.

The investigation reveals that Satoshi has been kidnapped in connection with two bank robbers. The clues ultimately lead Conan and Heiji to Satoshi's former house, where the case is resolved.

Satoshi Moriguchi is Mikihiko's friend, and concern over his disappearance brings Mikihiko into the investigation.

Mayumi Esaka is another member of Mikihiko's group of elementary-school friends.

Kenta Oosawa accompanies Mikihiko and Mayumi as another of Satoshi's friends.

Conan Edogawa investigates the disappearance and makes use of information provided by the children.

Heiji Hattori works with Conan to decipher the clues Satoshi leaves behind.