Daisuke Jigen is a smooth gunman who is the most often seen accompanying Lupin in his endeavors and heists. Despite Jigen disliking Lupin's lust for women, he remains Lupin's loyal and reliable partner to the end.
Creation and conception
According to Monkey Punch, Jigen's design was heavily inspired by American gangsters, with a loose basis on James Coburn's performance in The Magnificant Seven. In fact, Kiyoshi Kobayashi, the voice actor who dubs many of Coburn's performances into Japanese, was specifically selected to voice Jigen for the Lupin III animations.
The TokyoPop reissues of the original Lupin comics note in their preface that Jigen's appearance and temperament are based on the actor James Coburn, especially his role in The Magnificent Seven
In the original Weekly Manga Action run, Jigen's first appearance was in To Catch a Killer, where he was hired by the police as a hitman to take out Lupin for 2 million yen. Lupin was disguised as a driver, but Jigen recognized him, and thus didn't bother reading the letter that Lupin gave him. Despite Jigen trying to take him on, and knowing his overconfidence was his weakness, he had failed to take him out, and was seen dangling outside a window. Lupin was planning to kill him, but also failed due to the gun firing backwards.
After Lupin came out of hospital, he was surprised to see Jigen at his home. Lupin claimed that they were friends and grew up together, but because the Lupin Empire was crumbling, everyone became Lupin's rival, including Jigen. This makes them old friends & close in age. Briefly, Jigen became a henchman to King and was upset by Lupin's "death". He didn't believe the news, so he unwrapped the bandages and found the victim was a doctor. He knew that King had killed Lupin II, but was abused and was forced to kill Lupin, as his sister was taken hostage off-panel. Lupin told him King was dead; Jigen was surprised, but was concerned about what happened to Lupin's other shoe.
Since then, he had become Lupin's loyal partner and friend. His status as Jigen’s back-stabbing lackey or best friend & partner varied from volume to volume, due to a lack of consistent chronological storytelling or continuity.
After the original run, the manga was collected into volumes, with the chapters rearranged. Jigen appears abruptly as Lupin's right-hand man in Lupin III Chapter 7, later adapted to Part 1 Episode 2, which is currently Jigen's official manga debut.
In the manga, it is mentioned that Jigen has a sister, as well as a brother who had been killed by a man named Kido. This only applied to the original manga by Monkey Punch, as later manga more closely resembled the anime.
According to the Red Jacket Series (Lupin III, Part 2) and The Woman Called Fujiko Mine, Jigen was born in the Bronx, New York, and he joined the New York mob at a young age. Joe of Spades had taught Jigen how to use a gun, and when he was on the run from the law, Catherine Moro wanted to be with him however he ran off. He was also a mercenary who went to South America and befriended Gallanco, whom he admired, and who also taught him how to use a gun. They both went to Dolminea to fight in a war; the image of Gallanco becoming a hero left a deep impression on Jigen. At some point, he relocates to Europe and joins the Italian mob, although the reason is unknown.
While in the Italian mob, he grows close to his boss's wife, Cicciolina. This boss eventually catches wind of this, and tries to kill Jigen, but is accidentally killed by Cicciolina when she tries to stop him. Jigen arrives at the scene first and takes the gun from her hands, which later becomes his signature weapon and most prized possession. Seeing Jigen with the gun, the other mobsters assume that Jigen killed their boss and pursue him. Jigen manages to escape and later takes a job with the rivalling Chinese mafia.
Later, after Fujiko is hired by Cicciolina to steal Jigen's Magnum, Jigen and Cicciolina meet in a church. Cicciolina points Jigen's magnum at him, but before she can shoot, Jigen kills her only to discover that her gun was not loaded and that she had never intended to kill him, but only wanted his help in her suicide.
Afterward, he tells Fujiko he has had enough of killing, and decides to become a thief. Later in the series, he meets Lupin and the two become partners. In the episode "Revenge of the Golden Butterfly", he reveals the first job he and Lupin did together was a bank job.
In the anime series, Jigen is extremely loyal to Lupin and almost always partners with him for any given mission.
In the manga, Jigen is introduced as a cynical, backstabbing, lazy, henchman, with whom Lupin never gets along. He evolved into an easily-amused, loyal, & jolly best friend & partner-in-crime, who occasionally brawls with Lupin over petty things. He was never a famous marksman, quickdraw, or sniper - in fact, Fujiko & Lupin could draw faster than him. He rarely hit on women, but when he did, it was sleazy, with a keen interest in girls who play hard-to-get. Unlike Lupin, though, he never scored and was often beaten up by girls. The main remnants of his original personality that carried over to the anime were his cynicism, deadpan snarking, sense of caution, and disgust for Lupin's tireless pursuit of women.
Despite Jigen's gruff facade, he has an ironic sense of humor and genuinely enjoys taking part in each caper with Lupin and Goemon.
His distrust of woman stems from his many failed romances (his luck with women runs from bad to worse, with love interests often betraying him or dying). He especially distrusts Fujiko, and becomes irritated when Lupin goes along with her schemes. In the manga, it may have stemmed from the fact that Lupin was always too busy screwing girls to pay any attention to him.
Among Lupin's group, Jigen is the least apprehensive in taking human life. While he refuses to kill women and children, he is willing to put down any man who poses a threat. Also, in Lupin III vs Detective Conan, he seems to dislike it when Conan Edogawa calls him "Papa".
Jigen is a heavy smoker, smoking about 60 cigarettes a day according to The Mystery of Mamo DVD booklet. A running joke in the series is that his cigarettes always end up bent out of shape. His favorite cigarettes seem to be either Marlboro Reds (as in Falling Cherry Blossoms - The Mysterious Gang of Five - Part II and Lupin the Third Part 5) or Pall Mall (as in The Mystery of Mamo and The Woman Called Fujiko Mine); he's also occasionally seen smoking a briar pipe. He has also smoked Lark cigarettes with Lupin in Fujiko Mine's Lie.
A recurring character trait is his fear of the dentist. In the first episode of the second series, Jigen says that his tooth throbs whenever he gets excited or jumpy. In Tokyo Crisis, an aching cavity he refuses to have fixed detracts from his aim. He is also afraid of Iron Maidens, as seen in Hot Shot: This is Fujiko.
Jigen is the "big brother" of the group, and often serves as the voice of reason to Lupin's impulsiveness, often out of his friendship with Lupin, as well as sheer professionalism. However, he has long since resigned himself to going along with the craziest of schemes. Jigen also has a rough temper and tends to become violent when someone makes an inappropriate crack, from which even Lupin and Goemon aren't safe; though devoted to both, Jigen still has historically punched, wrestled, or threatened each with violence for relatively minimal infractions, done more as friendly payback than severing ties. One example is in The Castle of Cagliostro, when he wrestled a secret out of Lupin.
Jigen's off-time is usually spent on watching sports, fishing, gambling, target practice, billiards, listening to classical music, and general lounging. He has a deep affection for spaghetti westerns and boxing. He's partial to American food, in particular steak, potatoes, burgers, and pizza. In $1 Money Wars, Jigen orders a Dry Manhattan cocktail instead of his usual drink, prompting Lupin to call Jigen homesick.
He enjoys beer and hard liquor, usually scotch. He rarely socializes and typically stays close to home. Due to his habitual distrust of women, he doesn't tend to date unless there's a strong mutual attraction.
Jigen, like the rest of the Lupin gang, is adept with disguises and can pilot virtually any motorized vehicle, including planes and tanks. He is also a tough hand-to-hand opponent, capable of knocking out an attacker with one blow.
He is a man of his vices & doesn't like to see good things go to waste. He spends his money on antique guns, alcohol, cigarettes, hats, expensive Italian designer suits (that somehow all look alike) such as Givenchy, Fendi, & Prada. He's notorious for stealing all the meat out of hotpots, or even off Lupin's plate, if he's distracted.
- Further information: Daisuke Jigen/Gallery
While Lupin and Goemon both have unique sartorial tastes, Jigen is rather minimalist. His typical wardrobe is a grey or black suit, white or light-colored dress shirt, black tie and his ever-present grey (or black) broad-brimmed black-banded fedora; the hat ranks as his most prized possession, aside from his weapons. Even when he changes the rest of his attire, he keeps his hat on, and only removes it when mourning a death or on very formal occasions.
In Part 2, his suit is a grayish shade of green. In Part 3, Jigen's outfit is more light-colored and his hatband has a herringbone design (similar to the original manga interpretation of the character); however, the Black look is the most used for OVA productions and TV specials. Jigen's thick hair is typically collar-length and unevenly cut. His chin curtain beard is unruly, at about an inch long.
Jigen is a master thief and The Lupin Gang's key marksman. He can perform a 0.3-second quick-draw and has an accuracy that borders on superhuman; he can shoot skeet with a handgun, explode a missile before it hits by targeting the warhead, and deflect another bullet by shooting it in mid-flight. He prefers to conceal his eyes using his hat, as it gives him a more enigmatic appearance; when one or both of his eyes are seen, it is occasionally used to demonstrate surprise.
In the Red Jacket Series, it is revealed that he uses a notch in the hat brim to aim, but Jigen can shoot excellently without his hat; in the very same series, he makes shots from angles where his hat's notch would be useless, and even during times he is not wearing his hat at all. He is also proficient with many different types of firearms, such as machine guns, sniper rifles, and even a PTRS Anti-Tank Rifle.
His preferred weapon is a Smith & Wesson Model 19 revolver chambered in .357 Magnum, due to its stopping power and reliability. He isn't as fond of Lupin's Walther P38, because it has "recoil like a call girl". Jigen keeps his Magnum in a fabric holster specially built into the back beltline of his pants.
He feels quite naked without a gun: during an enemy attack in The Plot of the Fuma Clan, Jigen was unarmed (during a wedding) yet instinctively tried to draw, aim, and fire before realizing what he was doing. Even Lupin has joked that he should "buy it a ring and marry it already".
Jigen also carries a few rounds of special ammunition, such as armor-piercing shells and his own custom-made rounds to use as circumstances dictate. As he frequently travels by air, it's not been made clear how he successfully gets his weapon through airline checkpoints. One theory is that he flies unarmed and has weapons planted at all major airports, picking them up and leaving them when travel demands.
In the opening of the video game, Treasure of the Sorcerer King, Jigen assembles his pistol from composite parts and fires a shot through a door with 100% accuracy before an enemy can finish turning the doorknob. A similar situation is shown in episode 99 of the second series, "The Combat Magnum Scattered in the Wasteland." where Lupin steals Jigen's gun, takes it apart and leaves a trail of gun pieces leading to the border. Jigen is able to avoid being shot by an expert marksman, reassemble his gun, and then turn around to kill his enemy.
As seen in Shooting Orders!!, Jigen has extensive knowledge of guns and firearms, mainly due to him being around them so much.
Jigen often acts as a driver for the Lupin gang, and a lookout. In addition to his firearms skills, he is skilled in hand-to-hand fighting in case he is disarmed. A few times, he has wrestled while trying to keep Lupin under control, most famously in The Castle of Cagliostro. Like Lupin, he also wears disguises, and on rare occasions also disguises himself as Zenigata.
The character was portrayed by Kunie Tanaka, in the Japan-made live-action film Lupin III: Strange Psychokinetic Strategy. He has also appeared in a Case Closed special called, Lupin III vs. Detective Conan.
- In the Italian versions, his name is Jigen Daisuke. This means that his first name is Jigen while his last name is Daisuke rather than the other way around.
- According to The Castle of Cagliostro Dictionary Book, Jigen's birthday is on November 29. This is the only time when a date for his birthday was given. 
- Jigen makes a cameo appearance as a farmer driving a yak-drawn wagon in the Animaniacs episode Sir Yaksalot. This was because TMS Entertainment was involved with the episode.
- In the English Streamline dub of Wings of Death - Albatross, Jigen states that two things he hates are garlic and radiation burns.
- Due to his association of smoking cigarettes, in Italy there are tobacconists named after him  and his bent cigarettes has a slang term called "alla Jigen" (like Jigen). 
- A character based on Jigen appeared in the Samurai Jack episode, "Jack and the Labyrinth". He was only known as The Thief. In the Japanese dub, Kiyoshi Kobayashi himself voices the character.
- In the first French dub of Lupin the Third Part II, his name was inconsistent. In some episodes he was nameless and only referred to as the other or the bearded man. In Aim for the Oildollar, it was given as Augustus. Isidore first appeared in The Rose and the Pistol and then Shoot into the Midnight Sun, Killing Is the Smell of Wine and Lupin Will Fetch a High Price Jigen's original name appeared in Cornered Lupin, The Great Thief Nezumi-Koozoo Makes His Appearance and Lupin, Whom I Loved - Part Two. Lupin, Whom I Loved - Part One switches between Isidore and Jigen.
- Jigen's voice actor, Kiyoshi Kobayashi, also voices General T. Jefferson from Golgo 13: The Professional. Jefferson sounds similar to Jigen when he is in his jealous state.
- Jigen collects guns of varying calibers & sizes, but his primary three, depending on the media, are a Magnum, a Colt, and a Smith & Wesson.
- According to episode 152 of Red Jacket series Jigen's hat's size is 58.2 cm and its brim is 8.6 cm.
Jigen has been referred to in other anime and manga such as Excel Saga. Anime historian Carl Horn has described Jigen as "the epitome of cool".
- Further Information: Daisuke Jigen/Voice Actors
- Kiyoshi Kobayashi
- Banjō Ginga (Lupin III: The Plot of the Fuma Clan)