Lupin III/WMG

One or more of the characters is a Time Lord.
Does this just get added to all the pages by the template or something?
 * Lupin is a Time Lord, the Fiat is his TARDIS (it's clearly bigger on the inside and obeys no physical laws, just watch Cagliostro), and he only changes jackets when he regenerates. There. Obligatory post done.
 * And the original Lupin was the same person. Lupin the 3rd isn't really the grandson of the first Lupin, he is merely his third incarnation. He regenerates into a younger body, lays low for a while, then shows up claiming to be descended from the previous Lupin. He's much older than he looks, which explains how he's had time to become really good at being a thief.
 * Might go some way to explaining why he hasn't aged since the 1960s. Seriously, to make the timeline work, he'd have to be Lupin IV by now.
 * And the appearances of Arsene Lupin and Lupin II alongside Lupin III in the manga can be explained by it taking place in an alternate universe.

Shin Nohara is Lupin's son
His real name is Shin Lupin or Lupin the Fart. He has the color scheme of the original Lupin.
 * He's living with Fujiko Mine's flat-chested sister Mitzi (Fujiko stole her boobies in the womb) and her husband Hiro.

Castle of Cagliostro is a sequel to the rest of the Lupin series.
Throughout Castle of Cagliostro Lupin is a perfect unsullied gentleman thief, a portrayal directly contrasting those sleazy depictions of Lupin the III featured pretty much everywhere else. Any apparent discrepancies in Lupin’s character can easily be attributed to character development.
 * Like real-world Cuba it only looks like the seventies because of the Principality of Cagliostro’s relative isolation, clearly resulting from Count Cagliostro’s authoritarian administration.
 * The International Police Criminal Organization’s seventy-ish vehicles, equiptment, and uniforms are the result of Interpol’s limited budget; possibly second hand from other law enforcement agencies.
 * This doesn’t account for the explicit presence of Soviets and West Germans at the Interpol meeting.
 * The Soviet block obviously never collapsed in Lupin.
 * Both the Soviet Union and West Germany possibly reform in the future.
 * Russian and German representatives were merely doing a little historical reenactment at ICPO conference, it’s an international police thing.
 * Silly Tropers... the film is nothing else but Miyazaki's own continuity to the series. He didn't know moar episodes would follow. So all the films AND episodes that would follow after should be considered "alternate continuity". ... A wild guess, but an educated wild guess.
 * Semi-confirmed, actually, as Miyazaki felt that the movie was about Lupin "in the twilight of his career"
 * Who’s the silly Troper now? Your attempt to Joss has been Jossed by word of Miyazaki!

Zenigata is actually Lupin's father, Lupin II

 * Why else would Lupin call Zenigata Pops? Zenigata is obviously ashamed of his father and disappointed in his son.
 * In the original Japanese, it's "ossan", a somewhat informal term that's more used to refer to maybe an uncle and/or friend of the family, not really something you'd call your own dad. Whether or not that josses the WMG is up to the reader.

The Arsene Lupin seen in Night Hood is actually Arsene Lupin Jr. Son of the original and father of Lupin III
The timing is just barely about right and his characterization is much colder and and business-like than the original (possibly from having to live and/or serve during the First World War), and he bears a striking physical resemblence to the anime character, the only major differences between them being Night Hood's lighter hair color and blue eyes.

There is no single Lupin III.
Drawn from the often-confusing Green vs. Red, this theory states that Lupin is not a single individual, but an identity adapted by successive people inspired by the outlaw. There may have originally been a Lupin III who was the biological descendant of the original Arsene Lupin, but as time wore on, different people took up the mantle of the master thief, and the best of these imitators became recognized as "Lupin III". This explains how Lupin does not seem to age over the years, although it would not explain why his companions and Zenigata have not shown signs of aging. Green vs. Red also seems to suggest that the original Lupin III is still alive, guiding his successors from the shadows.
 * The original concept of Fujiko was just "the girk of the week is named Fujiko", and clearly, Lupin just names the Biggest-breasted woman he sees as Fujiko. When he has the skills to provide them with an entirely new identity as this woman, why would they object?
 * Still doesn't explain the other three.
 * Jigen and Goemon are the same as Lupin: they follow the current Lupin while training a successor, and when the moment is right the successor quietly replaces the original one. Zenigata, instead, has his brain transplanted in a new cloned body every time the previous one fails due too much abuse and his poor diet.

Riko Mine is the daughter of Lupin III with Fujiko Mine.
Because it's too damn obvious a crossover NOT to be true.

The imitators of Lupin in Green Vs Red represent every version of Lupin to ever have existed.
The Rupan references are from a character calling himself Rupan the Third. Afro and pink jacket are because that one represents the third series. The main character represents every new writer and Cosplayer who try to make a Lupin. The crazy helicopter pilot Lupin is that 12-year-old kid who is LARPing Lupin "because he blows stuff up and steals 'cause he can!", which is to say the guy who sees Crazy Awesome and thinks it means Crazy + Awesome.

Fujiko is the evil sister of Yukiko Kudo.
Here it goes. Although they look different, they got the same hair color and length. It would appear that the latter was once a thief like the former as they go on crime sprees together. This is where she gets the disguise idea. The thing is Yukiko is a good person, despite everything she had done. Later on, she finally got fed up with Fujiko's backstabbing ways that she left her after a heist. Yukiko becoming an actress and being part of the Kudo family is meant to be her redemption. Makes sense, huh? Imagine if those two meet again, it's gonna be one hell of a fight between them.

Lupin watches too much cartoons.
Kinda explain of disobeying the laws of physics, huh? Gotta thank the likes of Bugs Bunny and the Pink Panther.

The four fan-suggested episodes (100-103) predicted four major Fan Fiction types/characters.
Which makes sense when you think about it. Episode 100 gives us shades of the Boys Love Genre in the form of Nai Baba, the shiek with the hots for Zenigata. Episode 101 basically gave us a Crossover with Rose of Versailles. Episode 102 has Brilla, who could be classified as a Mary Sue; she's impossibly cool and clever, gets taken on a date with Lupin, and Lupin ends up helping her in the end instead of robbing her. And Episode 103 makes Goemon inexplicably Bishonen, complete with wings and sparkles.