The series originated from two one-shot stories, 'City Hunter -XYZ-' and 'City Hunter -Double Edge-', which were well received before the weekly serialization began in Weekly Shōnen Jump in 1985; these one-shots take place in a parallel world with different character designs and personalities, notably a very different Kaori, so they were never included in the regular tankōbon collection.
Despite strong tankōbon sales, the manga's popularity within the magazine itself was initially low because its hardboiled tone was considered too mature for a shōnen audience.
To make the series more appealing, first editor Nobuhiko Horie suggested Hojo add 'mokkori' (a comedic euphemism for arousal) gags, which Hojo took literally, and this shift toward comedy is credited with turning the series into a hit.
In the early 1990s, internal turmoil at Shueisha disrupted the manga's editorial support, and the series was abruptly given only four more weeks before cancellation, forcing an unplanned ending; Hojo later added about 30 pages to the collected edition so the story wouldn't end on a bad note, and his lingering feeling of not having finished the story properly led him to create the spin-off/remake series 'Angel Heart'.
Because heroine Kaori was designed as a boyish character considered unlikely to appeal to male readers, Hojo made a rule to always introduce a new glamorous 'beautiful woman' guest character in each story arc, and deliberately avoided differentiating their faces so as not to stray from the reader-favored 'Hojo beauty' template.
Kaori's given name was taken from the newborn daughter of Hojo's editor Nobuhiko Horie at the time.
Hideyuki Makimura's facial design was based on a slightly longer-faced version of Hojo's own self-portrait, while his surname was borrowed from manga artist Satoru Makimura.
Hojo has stated that Makimura was created from the start as a character destined to die, introduced purely to establish the backstory of how Ryo and Kaori became partners.
Because depicting drug use was difficult for broadcast standards, the TV anime's staff self-censored and completely omitted the drug 'Angel Dust' and the criminal organization Union Théopolis from the original TV series, replacing them with a new fictional gang called the 'Red Pegasus'; Union Théopolis and its leader Kaibara only appeared in animated form for the first time in the 2023 film 'Angel Dust'.
In the anime continuity, Angel Dust was redefined from a literal drug into a nanomachine-based technology that enhances physical ability, with the production deliberately avoiding visual cues that would evoke real drug use.
Ryo Saeba's signature red Mini Cooper Mk.I did not appear until relatively late in the manga (chapter 31, first published in 1986); earlier chapters instead frequently featured a Honda CR-X, while the anime featured the red Mini Cooper from its very first episode onward.
According to a 2019 BMW Japan interview, Hojo chose the Mini Cooper for Ryo's car because he liked its design and because its small size helped visually convey the narrow streets of Shinjuku and the physical closeness between Ryo and Kaori; Hojo originally envisioned the car in British Racing Green, but it became fixed as red after the anime's color designation.
The manga license plate on Ryo's Mini Cooper reads a sexually suggestive number ('69' and '19-19' referencing Kabukicho), while the anime version changed the numbers to the less suggestive '32-98' to tone down the joke; the French live-action film's plate follows the anime's numbering but adds 'NL' for Ryo's French name, Nicky Larson.
The manga's Mini Cooper is shown with a twin-tank fuel filler design accurate to the real Mk.I Cooper S, and Hojo is believed to have used a Tamiya 1/24 scale model kit of the Morris Mini Cooper 1275S Mk.I as reference art, which explains custom details like the aluminum wheels and bumper overriders appearing consistently in the manga.
Because original Mk.I Minis are now rare collector cars, the 2019 French live-action film used a later Mk.III model modified with fender mirrors instead of door mirrors to better match the manga's look, a detail insisted upon by director and star Philippe Lacheau, a big fan of the series.
Jackie Chan starred in the 1993 Hong Kong film adaptation after fans told him he resembled Ryo Saeba, which is what led to the project being made.
Voice actor Kōichi Yamadera, who played the recurring assassin character Ginfox (Silver Fox) starting from episode 6 of the first anime series, later also provided Ryo Saeba's dubbing voice in the 2019 French live-action film.
Voice actor Hiroya Ishimaru, who voiced the villain David Clive, later performed the Japanese dub voice for Jackie Chan's Ryo Saeba in the 1993 live-action film.
In the French dub and subsequent French media, Ryo Saeba is renamed 'Nicky Larson,' which is why the 2019 French film's original title translates to 'Nicky Larson and Cupid's Perfume.'
Due to internal corporate turmoil at Shueisha in the late 1990s, Hojo's longtime editor Nobuhiko Horie left the company to found Coamix in 2000, joined by Hojo himself, fellow manga artists Tetsuo Hara and Ryuji Tsuhara, and voice actor Akira Kamiya (Ryo Saeba's voice); as a result, City Hunter publications since roughly 2003 have been released through Tokuma Shoten rather than Shueisha.
Voice actor Akira Kamiya has named Ryo Saeba as his favorite role among his career and named his own voice acting talent agency 'Saeba Corporation' (Saeba Shoji) after Ryo's fictional company.
As of December 2020, cumulative sales of the collected volumes had surpassed 50 million copies.
