TV-Series
Description
Professor Hiroshi Agasa, commonly addressed as Professor Agasa and known in some English localizations as Hershel Agasa, is an inventor in his early fifties who lives next door to the Kudo family in Beika, Tokyo. He holds a doctorate in engineering and supports himself through a wide number of patents and inventions, including video games that the children of the series enthusiastically test. He has been a friend of Shinichi Kudo and Ran Mouri since their childhood, and he becomes the first person to learn that Shinichi has been shrunk into the body of a child. After being convinced of Shinichi's identity, Agasa advises caution in dealing with the Black Organization and helps establish the boy's new identity as Conan Edogawa, including enrolling him at Teitan Elementary, where Conan meets the children who later form the Detective Boys. When Shiho Miyano, a former Black Organization scientist, flees the organization and collapses near his home, Agasa takes her in, learns her true identity, and helps her assume the new identity of Ai Haibara. He also trusts Shinichi's parents with the secret of what happened to their son.

Agasa is a jovial, caring, and outgoing person with many friends in his community, and these connections help him conceal the true origins of Conan and Haibara by presenting them as children of friends and acquaintances. He is highly intelligent and notably proud of his inventions, some of which have been recognized well enough to be used in official events. Although he is a bachelor, he is deeply paternal and enjoys spending time with the Detective Boys. He has a particular fondness for pasta and tomato juice, and he is remarkably lucky at winning prize tickets for food-related events, a trait that sometimes provides the group with unexpected outings.

Physically, Agasa is an average-sized man with a slightly overweight frame who looks somewhat older than his actual age. He is bald on the top of his head with the remaining hair silver, and he has thick eyebrows, a mustache, a somewhat bulbous nose, and round glasses. He is regularly seen in his lab attire.

Within the story, Agasa acts as Conan's closest technological ally and one of the few people who knows his true identity. He invents the special gadgets that allow Conan to operate as a detective while concealing his secret, including the voice-changing bowtie, the stun-gun wristwatch, the power-enhancing kick shoes, the tracking glasses, and the turbo-powered solar skateboard. He also creates the Detective Boys' badges and flashlight watches. He owns a yellow Volkswagen Beetle that is unreliable and often breaks down during trips, and he frequently drives the children to various locations, school events, and excursions, many of which turn into criminal cases. Because he knows about Shinichi and Shiho, Agasa is fully aware of the Black Organization and its crimes, and although he does not confront the organization directly, he is actively involved in helping Shinichi and his allies plan against it.

Agasa's relationships are central to his role. With Conan, he is a mentor, confidant, and trusted adult who keeps the boy's secret and provides the tools and support needed for his detective work. With Ai Haibara, he becomes a guardian and fatherly figure, taking responsibility for her safety and well-being while she lives in his home. The Detective Boys look to him as a kind professor who supervises their activities, and Ran Mouri trusts him to look after Conan. He also maintains a close friendship with Shinichi's parents, Yusaku and Yukiko Kudo, having shared the secret of their son's condition with them, and he is among the few characters who knows the full secrets surrounding other allies such as Subaru Okiya, keeping those identities safe.

Agasa's past includes attending Teitan Elementary and Okuho Middle School, and he has a family history connected to his uncle Kurisuke Agasa, a wealthy accountant who enjoyed gadgets, and his aunt Teiko. His development over the course of the series sees him grow from a somewhat eccentric neighbor and inventor into a dependable guardian and strategist, taking on greater responsibility as the caretaker of Haibara and as a key participant in planning against the Black Organization. His inventions also develop over time, with upgrades such as internal batteries for the solar skateboard reflecting his continued support of Conan's efforts.
Cast