A girl who used to be called Miyano Shiho and was in the Black Organization under the code name Sherry. After the Organization kills her older sister Miyano Akemi, Shiho takes the same drug that shrunk Kudou Shin'ichi and likewise becomes a child herself to escape, renaming herself Haibara Ai. She is blunt and cool-headed, but becomes frightened whenever the Organization is discussed or nearby.
Her name comes from fictional detective Cordelia Gray (灰 = gray) and Sherlock Holmes character Irene Adler.