The Secret of Twilight Gemini is the 8th Lupin the 3rd television special.
Tipped off by his old boss about a valuable treasure in the Moroccan desert Lupin, accompanied by trusty sidekick Jigen, and would-be girlfriend Fujiko, head off to find the riches. Nothing is easy however, and soon Lupin's old nemesis Inspector Zenigata is hot on his tail, and worse still a bunch of mysterious assassins are also not far behind. Can Lupin find the Twilight Gemini diamond, and uncover the secrets of the Gelt tribe before it is too late?
- Kanichi Kurita as Lupin III
- Kiyoshi Kobayashi as Daisuke Jigen
- Makio Inoue as Goemon Ishikawa XIII
- Eiko Masuyama as Fujiko Mine
- Gorô Naya as Inspector Zenigata
- Aya Hisakawa as Lara
- Takayuki Sugo as Jean Pierre
- Shuuichirou Moriyama as Dalune
- Eken Mine as Elder
- Nachi Nozawa as Sadachiyo
- Tetsuo Kanao as Zora
- Kazuhiro Nakata as Priest
- Mitsuaki Hoshino as Conductor
- Koichi Kitamura as Bultokari
- Kouji Ochiai as Masked Man
- Yutaka Shimaka as Shopkeeper
- Yuzuru Fujimoto as Chief
- Yoshiko Suzuki as Lady
Italian ("Una cascata di diamanti" [Mediaset] / "Il segreto del Diamante Penombra")
- Roberto Bianchi as Lupin III
- Sandro Pellegrini as Daisuke Jigen
- Antonio Palumbo as Goemon Ishkawa XIII
- Alessandra Korompay as Fujiko Mine
- Rodolfo Bianchi as Inspector Zenigata
- Stella Musy as Lara
- Guiliano Santi as Jean Pierre
- Lorenza Biella as Grandmother
- Toni Orlandi as Captain
- Sonny Strait as Lupin III
- Christopher Sabat as Daisuke Jigen
- Mike McFarland as Goemon
- Meredith McCoy as Fujiko
- Phillip Wilburn as Inspector Zenigata
- Elly King as Lara
- Brad Jackson as Jean Pierre
- Brice Armstrong as Dalune, Elder
- Jerry Jewell as Sadachiyo
- Carlos Moreno as Zora
- Chuck Huber as Priest
- Julio Cedillo as Captain
- Kyle Hebert as Bultokari
- Laurie Steel as Attractive Lady, Grandmother
An edited and censored version was also released alongside the uncut version in the US, the cut version was also accidentally featured in copies of Lupin the 3rd: Movie Pack - First Haul. Nearly five minutes were removed compared to the uncut version and claims that it was edited for television however it was not aired on TV in the US. The run time of the censored version is 1:27:39 while the uncut version was 1:31:21. Due to a bug, there are no subtitles in the edited version despite technically having the option.
Similar to the Italian censorship, in the edited version Sadachiyo has some lines removed due to that the character is gay however the character still appears in selected scenes.
All of the run times mentioned below unless mentioned are from the original version:
- 6:33-6:57 - Lupin sits down and talks to a woman who holds his hands as he wants a traveling companion, then Lupin wants to kiss her. The cut version goes straight to Zenigata wanting to arrest Lupin.
- 16:15-17:31 - The scene where Fujiko removes her clothes as she wanted to know why Lupin went to Morocco as they attempt to have sex. Then Sadachiyo broke in, Fujiko screamed and Sadachiyo whipped the blanket off revealing Fujiko to be naked as they both wonder what happened to Lupin was heavily cut down.
In the edited version, the only parts that were kept in were Lupin and Fujiko being in the sheets, Sadachiyo and the soldiers being by the door, Sadachiyo breaking in while Fujiko screamed and only Sadachiyo asking where Lupin ran off to.
- 53:15-54:34 - When Sadachiyo uses the whip to strip Fujiko's clothes off and Jean-Pierre saying that Lupin has half of the diamond as Fujiko was willing to share the treasure 50/50 was cut down. The only parts that survived were most of Jean-Pierre's words outside of him saying that Fujiko is willing to betray Lupin and surprisingly saying to Sadachiyo that Fujiko can be tortured while enjoying the thought. Fujiko saying "I bet" was changed to a shot of Sadachiyo instead of her having her breasts out.
- 1:08:03-1:08:05 (1:05:31-1:05:33) - "Is this Heaven or Hell?" was changed to "Am I dead? Oh no." due to religious reasons.
- 1:08:50-1:10:02 - In the edited version, the scene where Lara takes her clothes off and goes to the pond was cut. Since the next part was an important scene due to half of the Twilight Gemini diamond being on her, a bra and panties was put on Lara rather than being naked like the original. The Discotek Blu-ray release recreates the edit since TMS does not have the master of the edited version as it was done by Funimation themselves. According to the credits Byron Watson, Aaron Davidson and Carly Hunter were responsible for the animated censorship.
Note: Due to Fandom policy, the wiki is not allowed to show the uncensored version of this scene.
The UK only got the uncut version on DVD.
In the Mediaset TV version as well as the Italian VHS release, all the references to Sadachiyo were censored because in the original, the character was gay.
- Laserdisc November 1996 (VPLY-70623, VAP)
- VHS November 1996 (VPVY-63899, VAP)
- DVD CD Packaging (VAP)
- DVD DVD Packaging (VAP)
- DVD 2015? The Pursuit of Harimao's Treasure & The Secret of the Twilight Gemini (Futabasha)
- Blu-ray March 17, 2010 Lupin the Third: Lupin the BOX -TV Special BD Collection- (VPXY-71910, VAP)
- VHS November 1999 Lupin III - Il diamante penombra (Medusa)
- DVD July 28, 2004 Lupin the 3rd Special - Il segreto del diamante penombra (Dynamic Italia)
- DVD 2005 Lupin the 3rd Special DVD Collection - il segreto del Diamante Penombra (1LUP10, DeAGOSTINI/Dynit)
- DVD 2008 Lupin the 3rd Movie DVD Collection - il Segreto del Diamante Penombra (1LM08, DeAGOSTINI/Yamato Video)
- DVD 2012 Lupin III Film Collection - il segreto del Diamante Penombra (Uscita 18, Yamato Video)
- DVD April 30, 2002 (Funimation) [Uncut version]
- DVD April 30, 2002 (Funimation) [Cut version]
- DVD Lupin the 3rd: Movie Pack - First Haul (Funimation)
- Blu-Ray November 24, 2020 [Uncut and Cut versions]
- DVD 9th September 2002 (MVM)
- DVD July 28, 2006 (SPVision)
- DVD February 18, 2021 Lupin III – TV-Special Collection (KAZE)
- Blu-ray February 18, 2021 Lupin III – TV-Special Collection (KAZE)
- DVD January 25, 2007 Rupan : Le Trésor d'Harimao / Le Secret du Twilight Gemini
- According to Hideki Mitsui who wrote the script for the episode, Nippon Television wanted to have a character who could surpass Clarisse de Cagliostro.  The idea of Lupin going into Morocco was inspired by the Arsène Lupin story The Teeth of the Tiger.The original plan was Don Dalune to be in reality Arsène Lupin a reference to how he was in the original book and Lara was his grand-daughter however NTV were aware of the copyright issues regarding the Lupin name since it would have been exported as Cliff Hanger: The Secret of Twilight Gemini at the time and told him that Lupin III cannot be connected to Arsène Lupin. .The final script only has a slight hint.
- The Funimation release changes the credits by shrinking the original credits into a smaller window while translating the credits at the bottom and the English credits on the side. During the credits, there is a purple right border on the animation that was not in the other masters. It also adds a "Lupin III Special Part 8" title card at the end of the TV Special.
- In the English dub, Kyle Hebert does voice similar to a high pitched Droopy for Cali.
- https://mobile.twitter.com/hide7_7/status/1118312683399303168 Hideki Mitsui Twitter
- https://mobile.twitter.com/hide7_7/status/1197343785023205377 Hideki Mitsui Twitter
- https://mobile.twitter.com/hide7_7/status/1118317632497655808 Hideki Mitsui Twitter