Kimiko Yamaguchi

Kimiko is professional and accustomed to guiding tourists through the waters around Koumi Island. She takes responsibility for diving activities and understands the risks involved in entering the island's marine environment.

Because her role is limited to the film's island case, little independent personal history is established for her. She is primarily characterized through her occupation and involvement in the investigation.

Kimiko has no supernatural abilities. She is an experienced diver and instructor with practical knowledge of underwater safety, diving equipment, and the waters surrounding Koumi Island.

Her professional skills allow her to guide less experienced divers and respond to the environmental hazards present around the island.

Kimiko becomes involved when Ran, Sonoko, and other visitors participate in diving activities around Koumi Island. During the excursion, unusual shark activity draws attention to a serious incident involving professional treasure hunters.

The discovery of Tayama's shark attack triggers a broader investigation. Because Kimiko works with diving equipment and was present around the relevant activities, she becomes one of the local people considered while investigators determine whether the attack was accidental.

Conan discovers that Tayama's equipment had been deliberately rigged with fish blood to attract sharks. The eventual investigation clears Kimiko and exposes Jouji Iwanaga as the person manipulating the treasure hunt.

Chika Mabuchi owns the Grotto diving shop with which Kimiko works as an instructor.

Ran Mouri and Sonoko Suzuki encounter Kimiko through their diving excursion on Koumi Island.

Conan Edogawa investigates the diving incident and examines the possibility that someone familiar with the equipment deliberately caused the shark attack.

Tomoyoshi Tayama is the treasure hunter whose shark attack turns the diving activity into a criminal investigation.

Jouji Iwanaga is eventually exposed as the person who rigged the circumstances surrounding Tayama's attack, clearing Kimiko of suspicion.