Hiroki

Hiroki is a young elementary-school student who cares deeply about his pet cat, Akira. When she disappears, he trusts the newly formed Detective Boys enough to ask them to search for her.

His recurring requests concerning Akira suggest that he has become comfortable relying on the children when his adventurous cat wanders away. The series gives him relatively little characterization outside these appearances, and he remains primarily an ordinary classmate rather than an investigator himself.

Hiroki has no established special abilities. He is an ordinary seven-year-old student and does not participate directly in the dangerous investigative work that follows his request.

His connection to the Detective Boys is nevertheless important because his missing-pet request gives the newly formed group one of its earliest genuine jobs. The apparently mundane assignment demonstrates how the children's everyday activities can unexpectedly lead Conan Edogawa into serious criminal cases.

Hiroki asks Conan Edogawa, Ayumi Yoshida, Mitsuhiko Tsuburaya and Genta Kojima to find his missing cat Akira. The children eventually locate her emerging through the window of a nearby house with blood on her fur.

The discovery leads the Detective Boys inside, where they see what appears to be a corpse in a bathtub. When Juzo Megure and the police arrive, however, the body has disappeared, turning Hiroki's simple missing-cat request into the Missing Corpse Murder Case.

Conan eventually determines that Tomofumi Tanaka murdered his older brother Kazuyoshi Tanaka and manipulated the body, an answering machine and the layout of the house to create the illusion that both brothers were still alive. Hiroki's cat had inadvertently led the children directly to the crime scene.

Hiroki later reappears in Zero's Tea Time and The Culprit Hanzawa, extending what was originally a small early-series role into a recurring connection with everyday life around Beika.

Akira is Hiroki's pet cat. She has a tendency to wander away from home, prompting Hiroki to seek help finding her and indirectly triggering the case in which he first appears.

Conan Edogawa, Ayumi Yoshida, Mitsuhiko Tsuburaya and Genta Kojima are Hiroki's fellow Teitan Elementary students and the Detective Boys he asks to locate Akira. Their successful search unexpectedly exposes a murder.

Hiroki's Mother appears with her son in The Culprit Hanzawa and looks after him as part of his family life in Beika.