Daisuke Jigen (次元大介, Jigen Daisuke) is a smooth gunman who is most seen accompanying Lupin in his endeavors and heists. Despite Jigen disliking Lupin's lust for women, to the end he remains Lupin's loyal and reliable partner.
While Lupin and Goemon both have unique sartorial tastes, Jigen is pure basics. 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 outside of his weaponry. Even when he changes the rest of his attire he keeps his hat on and only removes it when mourning a death or during very formal occasions.
During the third season of the anime, 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 most applied for OVA productions and TV specials. Jigen's thick hair is typically collar-length and unevenly cut. His chin curtain beard is about an inch long and also unruly.
According to the Red Jacket Series and The Woman Called Fujiko Mine, Jigen was born in the Bronx, New York. From a young age he joined the New York mob. At some point to relocates to Europe and joins the Italian mob, although it is unknown what the reason for this is.
While in the Italian mob, he grows close to his boss's wife, Cicciolina. This boss eventually catchs wind of this and tries to kill Jigen. Cicciolina tries to stop him and accidently kills her husband. 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 a gun, the other members of the mob assume that Jigen killed their boss and goes after him. Jigen manages to escape and later takes a job with the rival 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 magum 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 him to help her commit suicide.
Afterwards, 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 the first job he and Lupin did together was a bank job.
Jigen appears abruptly as Lupin's right hand man in chapter 7 of the original manga series. His origins are never explained, but he is portrayed as a hitman who would kill Lupin if the money was good. By the second manga series however, he has become Lupin's trusted partner and friend.
In the manga it is mentioned that Jigen has a sister.
In the anime series, Jigen is extremely loyal to Lupin and almost always partners up with him for a given mission. (This is not true in early chapters of the manga; later chapters more closely mirror the anime portrayal.)
Despite Jigen's gruff facade, he has an ironic sense of humor and genuinely enjoys participating in each caper with partners 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 one of her plans.
Among Lupin's group, Jigen is the least apprehensive at taking human life. While he considers killing women and children taboo, he is willing to put down any man who offers a threat. Also, in Lupin III vs Detective Conan he seems to dislike it when Conan Edogawa calls him "Papa".
Jigen is also a heavy smoker, smoking about 60 cigarettes a day according to the 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 boxed (as in Kooky Kabuki) or Pall Mall (as in Mystery of Mamo); he's also occasionally seen smoking a briar pipe.
Another recurring theme is Jigen's fear of going to the dentist. In the first episode of the second series, Jigen says that his tooth throbs whenever he gets excited or jumpy. In Crisis in Tokyo, he actually loses his ability to shoot straight (temporarily) from being distracted by an aching cavity he refuses to have fixed.
Jigen is the "big brother" of the group, and often serves as the voice of reason to Lupin's impulsiveness, as he must because of his friendship with Lupin as well as out of sheer professionalism. However, he has long since resigned himself to having to go along with the craziest of schemes. Jigen also has a rough temper and tends to become violent when someone makes an inappropriate crack. From this habit not even Lupin and Goemon are safe; though devoted to both, Jigen still has historically punched, wrestled or threatened each with violence for relatively minimal infractions, done more in a still-friends form of payback than a tie-severing injury. One example is in Castle of Cagliostro, when he wrestled Lupin to the point of the gentleman thief shouting for him to stop when he felt that Lupin was keeping secrets from him.
Jigen's off-time is usually spent watching sports, fishing, gambling, practice shooting, billiards, 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, making Lupin comment on Jigen's action by calling him "homesick".
As mentioned, he smokes heavily; he also enjoys drinking 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.