Pretty much every female Phantom Thief is at least somewhat based on the Kisugi sisters. The most prominent expies are Kasumi Aso from City Hunter (a professional thief who only steals on commission and for good reasons, who looks like Hitomi and ends up working at the Cat's Eye cafe for good measure) and Alex from Totally Spies! (based mostly on Ai's personality, with her same name in the French dub).
Keep Circulating the Tapes: When the now-defunct ImaginAsian carried the rights for the anime, only the first 36 episodes (first season) were subbed, aired, and released on DVD (which is rare to find) and the second season wasn't picked up due to the expiration of licensing rights. Averted, however, in the summer of 2013, when Nozomi Entertainment acquired the rights and subbed the second season, while re-releasing the previous one.
But now it's back in this status once again now that RightStuf has lost the license.
Ditto for the French dub of the same movie, they managed to get all of the Kisugi sisters' French voice actresses in addition to the French dub cast of City Hunter (except for Umibozu and Miki once again) to reprise their roles and interestingly enough, Ai Kisugi's French voice actor, Annabelle Roux was Miki's replacement VA in the 2nd season of City Hunter.
Technology Marches On: An early chapter of the manga revolves around a villain posing as a French art representative named Henriette Rubeal. The villain makes no attempt to alter her appearance, and the only reason her plan is unraveled is because the Kisugi sisters find an obscure photograph of the real Henriette in an old Japanese art magazine. It was perfectly plausible in the 80's for someone to not know what a visitor from a foreign country looked like, but nowadays, in a world with Google and cellphones, her deception would have been uncovered almost instantly. Even the anime adaptation (which was released only a few years after the manga began) altered the story so that the thief simply tied up the real Henriette and used a convincing mask to steal her identity.
Acting for Two: Drew Barrymore plays Amanda in the third story, briefly appears as James Woods's character's daughter in the first story, and appears as a girl in a commercial that the cat sees on a TV in the second story.
What Could Have Been: Word of God states that there was a prologue that helped explained the cat's motivations. The cat originally had a family in North Carolina. The parents woke up to find their daughter dead and believe that the cat stole her breath in the night. While the father tries to revive their daughter, the mother takes her husband's gun and chases the cat away from the house. It ended up being cut from the film against the director's wishes because they believed it was "too silly."