Professor Hiroshi Agasa, an inventor and engineer, resides next door to Shinichi Kudo's family home. He attended Teitan Elementary and Okuho Middle School during childhood, meeting Fusae Kinoshita in sixth grade before her family moved away and his relocated to the countryside. His family lineage includes a deceased great-uncle, Kurisuke Agasa, who had an interest in gadgets, and a great-aunt, Teiko Agasa, who died a year prior to the current timeline. He also has an unnamed cousin and a cousin's granddaughter. Agasa maintains a friendly, outgoing personality, enabling him to conceal the true identities of Conan Edogawa (Shinichi Kudo's shrunken persona) and Ai Haibara (Shiho Miyano's alias) by presenting them as acquaintances' children. He exhibits paternal affection toward the Detective Boys, frequently chaperoning their outings, which often involve criminal incidents. Agasa holds notable intelligence, possessing at least one advanced degree, and designs specialized gadgets like communication badges, tracer devices, and voice-changing bowties to support Conan's investigations. While some inventions malfunction, others gain official recognition. He demonstrates exceptional luck in winning food-related prizes and lotteries. Physically, Agasa appears slightly older than his 53 years, with a somewhat overweight frame, partial baldness, silver hair, thick eyebrows, a mustache, and a bulbous nose. Severe nearsightedness necessitates round glasses, a vulnerability exploited during his abduction in the OVA "A Challenge from Agasa! Agasa vs. Conan and the Detective Boys." He typically wears laboratory clothing. His involvement with Conan began immediately after Shinichi was shrunken by the APTX 4869 poison. Agasa became Shinichi's first confidant, advising caution against the Black Organization and helping establish the "Conan Edogawa" identity. He enrolled Conan at Teitan Elementary, leading to the Detective Boys' formation. Later, he discovered Shiho Miyano collapsed near his home after her escape from the Black Organization, took her in, learned her identity, and assisted her transition into "Ai Haibara." He also informed Shinichi's parents about their son's condition. In the OVA "A Challenge from Agasa! Agasa vs. Conan and the Detective Boys," Agasa devises a simulated kidnapping mystery for the Detective Boys. During preparation, he witnesses an actual kidnapping involving a girl in a van but is subdued with a stun gun by perpetrators Osamu Yoda and Miki Ogura and abducted. The incident underscores his reliance on glasses due to severely impaired vision without them. Conan and the Detective Boys resolve the case. Agasa owns an unreliable yellow Volkswagen Beetle and once possessed a valuable Persian rug that became evidence in a theft investigation, preventing its sale. His culinary preferences include pasta and tomato juice.