Ai Haibara, originally Shiho Miyano, served as a scientist within the shadowy Black Organization under the codename Sherry. Her parents, Elena and Atsushi Miyano, were researchers for the group’s “Silver Bullet” project until their deaths, officially deemed accidental. Trained from childhood to inherit their work, Shiho studied abroad in the U.S. before rejoining the organization in Japan at 13. By 18, she engineered APTX 4869, a toxin later found to induce rare cases of de-aging in lab mice. The drug became a tool for covert assassinations, notably used on Shinichi Kudo, who survived by regressing into a child. Following her sister Akemi’s execution by the organization for attempting to free them both, Shiho halted her research in defiance. Imprisoned and condemned, she ingested APTX 4869 to end her life but instead shrank to a child, fleeing through a garbage chute. Discovered near Shinichi’s home, she was sheltered by Professor Agasa under the alias Ai Haibara. Enrolled at Teitan Elementary, she joined the Detective Boys, confiding her identity to Shinichi—now Conan Edogawa—and aiding his crusade against the organization while pursuing an APTX antidote. Guarded and sardonic due to her traumatic history, Ai initially kept others at arm’s length but gradually bonded with Conan, the Detective Boys, and Ran Mouri. Her sharp intellect and pragmatism often clashed with Conan’s risk-taking, as she prioritized concealing their identities. Haunted by fear of the Black Organization—particularly Gin and Vermouth—she once believed herself a liability to allies. Over time, she embraced her new life, revealing protective instincts and moments of vulnerability, such as mourning Akemi. A pivotal strategist, Ai leverages her scientific acumen and insider knowledge of the organization. She reconstructs the APTX antidote from fragmented data, testing temporary versions that briefly restore her adult form. Collaborating with Conan, Yukiko Kudo, and Subaru Okiya, she staged her death during a train explosion to deceive the organization into believing Sherry perished—a ruse Vermouth concealed despite knowing the truth. Ai’s interests reflect her layered persona: an affinity for luxury fashion brands like Prada and Fusae, avidly read *ComCom* magazine, and admiration for soccer star Ryusuke Higo, whose betrayal by a team parallels her own past. Her U.S. upbringing left a fondness for peanut butter and blueberry jelly sandwiches, a habit abandoned after Agasa uncovered it. During the Scarlet Bullet incident, Ai partnered with Conan, the FBI, and the Akai family to unravel kidnappings tied to the World Sports Games and a maglev train crisis. Her analytical precision and caution proved vital in resolving the case, though the organization’s belief in her demise remains crucial to her concealed existence. Across her journey, Ai evolves from a fugitive burdened by guilt to a steadfast ally, balancing self-preservation with loyalty to those she protects.