Ai Haibara, originally Shiho Miyano, served as a scientist codenamed "Sherry" within the Black Organization. She created the APTX 4869 poison, which occasionally induces de-aging instead of death. Following her sister Akemi Miyano's murder by the organization, Shiho ingested APTX 4869 intending suicide. She miraculously survived, regressing into the body of a six- or seven-year-old child, and escaped. Exhausted, she collapsed near Professor Agasa's residence. He discovered her and provided refuge, unaware she was the daughter of his late acquaintances, Black Organization scientists Atsushi and Elena Miyano. Adopting the alias "Ai Haibara" for concealment, she enrolled at Teitan Elementary School. Initially cynical and guarded due to her traumatic past, she slowly forged connections with Conan Edogawa (the de-aged Shinichi Kudo), the Detective Boys, and Professor Agasa. Despite her reserved nature, she exhibits strong protective instincts towards these friends, whom she views as her first true relationships. She actively researches an antidote for APTX 4869, though progress is hindered by the destruction of most original data. Her personality combines high intelligence with dry wit, frequently revealing knowledge incongruent with her apparent age. She maintains vigilance to protect others from potential pursuit by the Black Organization. Haibara harbors niche interests, including a fondness for peanut butter and blueberry jam sandwiches acquired during her time in the United States. She displays an affinity for luxury fashion brands like Prada and Fusae, often requesting designer items as compensation for investigative assistance. She is a fan of the soccer player Ryusuke Higo and his team, Big Osaka, relating to his departure from a corrupt organization. In *Lupin III vs. Detective Conan: The Movie*, Haibara demonstrates unexpected skills linked to her past. She reveals she owned a Harley-Davidson motorcycle during her time as Shiho Miyano. During the film's climax, she operates a submarine to rescue Conan and Lupin III after their plane crashes near Hachijou Island. Her involvement occurs when Fujiko Mine, coerced by antagonists, requires aid. Haibara's technical expertise facilitates their escape. In the concluding scenes, she accompanies Conan and Ran Mouri to bid farewell to the singer Emilio Baretti, whose safety is secured following the case's resolution.