One night the Phantom Thief (the Gentleman Thief with Twenty Faces) steals a little girl. Her name is Chiko (Chizuko Mikamo). Until then, she had been a lonely girl. But that night , she embarks on a great adventure.
Experiencing freedom for the very first time, surrounded by friends, finding a place where she can be herself, Chiko starts changing gradually. A string of bizarre events start happening, centering around the tremendous mystery called the “Legacy of the Phantom Thief” and involving people with pathetic motives. Chiko has to move on nevertheless…no matter how checkered her life will be.
The “spiritual growth” of the dignified, innocent and beautiful girl, Chiko, (from the age of 11 to 13) is depicted in this action story that unfolds in a fast tempo. CHIKO, Heiress of the Phantom Thief is the first joint production between BONES (which produced Fullmetal Alchemist) and TELECOM ANIME (which produced Little Nemo and The Castle of Cagliostro–Lupin III).