Kazuo Koike, a Japanese manga writer whose dark samurai and action serials — most notably “Lone Wolf and Cub,” “Lady Snowblood” and “Crying Freeman” — influenced films by filmmakers Quentin Tarantino and Sam Mendes, died April 17. He was 82.

His Twitter account said he had been hospitalized with pneumonia, but did not say where he died. His death comes six days after that of Monkey Punch, his sometime rival, with whom he collaborated on the short-lived manga miniseries “Secretary Bird.”

Mr. Koike was perhaps best known for “Lone Wolf and Cub,” a samurai series that debuted in 1970 with art by Goseki Kojima. The serial revolved around Ogami Itto, a shogunate executioner whose family is murdered by a rival clan. Framed as the killer, Ogami is ordered to commit hara-kiri, but instead takes to the countryside as a ronin — a masterless samurai — seeking revenge. His infant son, Daigoro, accompanies him in a weaponized baby cart.

Clearly intended for adults, the pulpy series reflected darkly on the samurai code of conduct and the medieval Edo period. At the age of 1, Daigoro is given a choice by his father: Crawl toward a ball or a sword. If he chooses the ball, then Ogami will kill him. The child reaches for the sword, leading his father to become fiercely protective and allow him to live.

“One of the major themes is the parent-and-child relationship in Japan,” Mr. Keiko told the San Diego Union-Tribune in 2006, noting that Daigoro was modeled on his infant nephew. “The parent-and-child relationship today is not so good.”

In Japan, six films, four plays and a television show were adapted from the series. “Lone Wolf and Cub” also inspired an American graphic novel, “Road to Perdition” (1998), by crime writer Max Allan Collins. The graphic novel was the basis of a 2002 film of the same name, directed by Mendes and starring Tom Hanks.

Mr. Koike collaborated with artist Kazuo Kamimura on another 1970s revenge-themed serial, “Lady Snowblood,” centered on a 19th-century swordswoman who stalks the bandits who raped her mother and murdered her father. Director Toshiya Fujita’s 1973 film adaptation, replete with florid spurts of blood, was later acknowledged by Tarantino as an influence on his “Kill Bill” movies.

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Mr. Koike’s manga featured stylized graphic violence that benefited from the black-and-white color scheme of manga. He regarded most samurai films and manga as insufficiently violent and overly ritualized in their swordplay.

“Black and white gave him the ability to render blood graphically without the intensity that you would have in color,” said Andrew Farago, curator of the Cartoon Art Museum in San Francisco. “If you tried that in American comics, you wouldn’t get away with that and have mainstream distribution. It was a very cinematic approach, but it wasn’t gratuitous.” Mr. Koike and his artists, he added, “were very aware of the audience and the boundaries and limitations of what the publisher would allow.”

Although the series did not appear in a U.S. edition until 1987, Farago noted that its hyperkinetic style influenced American comic book artists such as Frank Miller (“Batman: The Dark Knight Returns”), Larry Hama (“G.I. Joe”) and Walt Simonson (“Manhunter”).

Mr. Koike later teamed up again with Kojima for “Samurai Executioner” (1972-1976), a series that recounted the stories of criminals killed by a neck-chopping ronin, often told as their final words before decapitation. His 1980s yakuza series, “Crying Freeman,” with artist Ryoichi Ikegami, chronicled a tattooed hit man who sheds tears before killing his victims.

Apart from the violent stories, Mr. Koike also wrote detailed manga about two of his favorite hobbies — golf and mah-jongg — and dabbled in American comics, writing a Wolverine story and a Hulk comic for the Japanese market.

Seishu Tawaraya was born in Daisen, near the Japanese city of Akita, on May 8, 1936. He adopted the pseudonym Kazuo Koike early in his career and collaborated with Takao Saito on the 1960s spy series “Golgo 13.”

Mr. Koike was inducted into the Will Eisner Comic Awards Hall of Fame in 2004. A complete list of survivors was not immediately available.

Mr. Koike established a training school for manga writers in 1977 and later taught manga at Osaka University of Arts. A good story, he believed, always begins with character development.

“I’ve only been teaching how to develop characters — never how to construct a story line,” he once said. “What I always try to do is persuade my students to create a strong character first. If you have a strong character, the story line will develop naturally, on its own.”

He added: “If you’re wondering how I teach my students to create good characters — to give them that starting point — I try to encourage them to make two characters that are polar opposites: God and Satan, night and day, North Pole and South. The struggle between these two characters develops the story. Having just one strong character doesn’t work. Having two characters as foils of each other is what sets things in motion.”