Breakaway Pop Hit: The anime and manga is basically a Cult Classic in its home country of Japan - outside of the scattered congregation of fans, most Japanese folks don't even remember itnote Which makes sense, since the anime targeted young adults in the early 80s, much of which are grandparents by now. The theme song on the other hand, went on to become a staple in Karaoke Boxes, lounges and bars in Japan, with reports claiming that it is often requested at least once a night at any given karaoke venues, and the generation who are unaware of the anime are still familiar with the song lyrics.
Colbert Bump: Due to popular youtuber Techmoan bringing up the theme song of the anime on his channel during his review of a portable karaoke system, videos of the theme song on Youtube suddenly surged in popularity, with many of the videos swarmed with irrelevant comments by said youtuber's subscribersnote A string of "blah"s due to Techmoan's extremely questionable performance of the song.
Pretty much every modern female Phantom Thief and Classy Cat-Burglar is at least somewhat based off the Kisugi sisters (when not based off Catwoman). 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 café 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.
In Memoriam: Due to the girls' guest appearance in City Hunter: Shinjuku Private Eyes, the movie's end credits feature a dedication in memory of Toshiko Fujita who was unable to reprise her role as Rui since she was very ill during the movie's production and died before it was released.
PIKACHU! MYSTERIOUS GIRL!note A meme originating from South America, due to the common mishearing of the last two line of the chorus of the theme song, properly "We got you! Mysterious Girl!"
I thought it was a cut lemon...note The Speedy Techno Remake of the song used a stylized drawing of a cat's eye in it's cover art. Most people misinterpreted the image and thought it was an picture of a lemon being cut in half.
The Other Darrin: While the Italian dub of City Hunter: Shinjuku Private Eyes brought back the original Italian dub voice actors for Ryo, Kaori, Saeko and Umibozu. All other returning characters were voiced by different actors, the Kisugi sisters' included. This is understandable since the Kisugi sisters' original Italian VA's are now busy with other projects and likely would've been too expensive to hire.
For the heroines' appearance in City Hunter: Shinjuku Private Eyes, Hitomi and Ai's voice actresses, Keiko Toda and Chika Sakamoto respectively, return to their roles. The role of Rui was Darrin'd to Toda due to her original VA, Toshiko Fujita being very ill during production and eventually died at the tail end of 2018.
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.
Speedy Techno Remake: The theme song was translated into English and performed by the controversial Europop group E-Rotic, and then received the trope thanks to Ventura.
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.
Uncredited Role: Thanks to the Blu-Ray releases, storyboards for several Season 2 episode attribute animation duties to several outside teams - Studio Iruka, Studio NASA and Animal Ya - who do not get credit in the episodes proper. Nakamura Productions, who are credited for in-betweens on almost every episode (minus Episode 6, also done by an uncredited Animal-Ya), are similarly left out of Episode 25's creditsnote animators Miyoko Mishima, Hisashi Hirai and Koichi Naito are given affiliation credit for their other episodes.
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.
Frank Welker does the voices for both General the cat and the Troll in the third story.
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." The film also originally ended with the cat being Evil All Along and stealing Amanda's breath. This was changed to a Happy Ending for unknown reasons (presumably due to the Fridge Logic of the cat following a little girl's telepathic plea for help halfway across the country and battling a troll to protect her, only to then kill the girl himself).
The second story was originally going to be an adaptation of Sometimes They Come Back, but was considered too dark to fit with the more "family-friendly" film. Though it got made into a TV movie in 1991.
on the other hand, went on to become a staple in Karaoke Boxes, lounges and bars in Japan, with reports claiming that it is often requested at least once a night at any given karaoke venues, and the generation who are unaware of the anime are still familiar with the song lyrics.