Ai Haibara

Haibara is calm, intelligent, sarcastic, and considerably more mature than the elementary-school identity she presents to the world. She rarely shares Conan's enthusiasm for rushing into danger and frequently points out risks that he has underestimated. Her dry humor and deadpan observations make her an effective counterbalance to his confidence.

She initially approaches relationships cautiously and expects danger to follow her. Over time, however, Haibara becomes deeply attached to Agasa and the Detective Boys. She is especially protective of the children even when pretending to be annoyed by their behavior.

Haibara also develops interests unrelated to her former life. She becomes an enthusiastic supporter of footballer Ryusuke Higo, follows fashion, and displays a softer side around animals.

Haibara is a gifted biochemist with extensive knowledge of pharmaceuticals, medicine, and the biological effects of APTX 4869. Her real identity is Shiho Miyano, the Black Organization scientist codenamed Sherry who continued her parents' research and developed the version of APTX 4869 responsible for shrinking both herself and Shinichi.

Her scientific knowledge allows her to analyze drugs, recognize medical conditions, and conduct experiments toward an APTX antidote. Because much of the original research data is unavailable, creating a permanent reversal remains difficult.

Haibara is also highly observant and intelligent outside laboratory work. She can assist Conan's deductions, recognize danger quickly, and has extensive knowledge in subjects ranging from art and classical music to history.

Haibara enters Conan's life as a mysterious transfer student at Teitan Elementary School. Her intelligence and adult manner immediately distinguish her from the other children.

She eventually reveals to Conan that she is Shiho Miyano, formerly Sherry of the Black Organization. After the Organization killed her older sister Akemi, Shiho refused to continue her research and was imprisoned. She swallowed APTX 4869 expecting to die, but instead physically regressed and escaped.

Living with Agasa gives Haibara a new identity and makes her a central source of information about the Black Organization. Her knowledge of its members and methods repeatedly helps Conan, while her own history makes discovery by the Organization an ever-present danger.

Conan Edogawa is Haibara's closest intellectual partner. Both are teenagers physically reduced by APTX 4869, and Haibara knows that Conan is actually Shinichi Kudo. Their contrasting attitudes toward danger produce frequent arguments, but they trust one another deeply.

Hiroshi Agasa takes Haibara into his home after finding her collapsed near the Kudo residence. He becomes her guardian and one of the people she trusts most.

Akemi Miyano is central to Haibara's past. Akemi is her older sister, whose murder by the Black Organization leads Shiho to rebel against the syndicate.

Atsushi Miyano and Elena Miyano are Haibara's parents and scientists whose research preceded her work for the Black Organization.

Ayumi Yoshida becomes Haibara's closest female childhood friend within her new life, while Mitsuhiko Tsuburaya and Genta Kojima likewise treat her as a genuine member of the Detective Boys.

Shuichi Akai has important connections to Haibara's family history. He previously dated Akemi while infiltrating the Black Organization and is also Haibara's cousin through the Akai and Miyano families.

Vermouth regards Haibara as a dangerous remnant of the Miyano research and becomes one of the Organization members Haibara fears most.