Professor Hiroshi Agasa, a 52-year-old inventor and longtime family friend, resides next door to Shinichi Kudo and maintains a close relationship with him and his parents. After Shinichi is forcibly shrunken to child form by an experimental drug, Agasa discovers him and becomes the first to learn the truth. Recognizing the danger from the shadowy organization responsible, Agasa creates the alias "Conan Edogawa" for Shinichi, drawing the name from mystery authors Edogawa Ranpo and Arthur Conan Doyle—whose books are visible on the Kudo shelf. Agasa convinces Ran Mouri that Conan is a distant relative requiring temporary care, facilitating his placement with Ran and her father Kogoro at their detective agency. This allows Conan to investigate the organization covertly. Agasa warns Shinichi that revealing his identity to anyone, including Ran, would endanger them both. Agasa provides ongoing support through specialized inventions for investigations and self-defense. He mentors Conan and his friends, forming the Junior Detective League, and extends emotional support and scientific expertise to another victim of the organization. Demonstrating consistent kindness and protective instincts, Agasa treats those around him with patience and care as a surrogate family member. His workshop functions as a safe haven and technological hub in their endeavors against criminal elements.