Directed by Sōji Yoshikawa, who co-wrote the screenplay with Atsushi Yamatoya, the film was produced by animation studio Tokyo Movie Shinsha and distributed by Toho.

The film's plot follows master thief Lupin III, who attempts to foil Mamo ― a wealthy and powerful recluse seeking immortality ― while trying to win the affections of his rival and would-be lover, Fujiko Mine.

The English dubs, though varying widely in terms of their production quality, interpretation of the dialogue and voice acting, have frequently been singled out for praise.

Zenigata travels to Egypt, believing that Lupin will raid the Giza Necropolis based on prior thefts of immortality-granting objects.

His prediction proves accurate, but Lupin and his colleagues Daisuke Jigen and Goemon Ishikawa XIII flee with the Philosopher's Stone.

Mamo, a mysterious billionaire officially known as Howard Lockewood, tells Lupin that he manipulated him into stealing the Stone as a test, as he is considering granting him and Fujiko immortality in admiration of his skills and her beauty.

Mamo deems Lupin unworthy of eternal life and attempts to visualize his perverted nature to Fujiko, but she refuses to abandon him.

They are thrust into a vision by Mamo, who reveals that his cloning technique has kept him alive for ten thousand years, and that he is responsible for virtually every major event in human history.

Inside a temple, Mamo explains to Fujiko that his cloning technique has never been perfected, and that he has degenerated from his original form as a result.

He decides that he and Fujiko must repopulate the Earth, and convinces her to push a button to launch nuclear missiles to achieve this end.

The Mystery of Mamo was produced while the second Lupin III television series was being broadcast, and was created with the intention of making a film that was aesthetically and thematically faithful to Monkey Punch's original manga, as censorship standards of the time prevented such content being reproduced for TV animation.

The movie was given a budget of 500 million yen, comparable to major live action films at the time and unheard of for an animated production.

Oversized cels were used and filmed in a modified VistaVision process known as "Anime Vision", which allowed for a brighter and sharper picture for projection in theaters compared to a TV production.

His physical design was inspired by Swan, Paul Williams' character in the 1974 musical horror film Phantom of the Paradise, and represents a monster who is both a boy and an old man at the same time.

[8] Footage from the film's first English dub, along with scenes from The Castle of Cagliostro, was used by Stern Electronics (under license from TMS) to make the Dragon's Lair-style laserdisc video game Cliff Hanger.

[10] To commemorate the 50th anniversary of the Lupin III franchise, The Mystery of Mamo received a limited theatrical re-release in Japan on September 1, 2017, utilizing a newly remastered print in 4K resolution, a 5.1 surround sound mix and 4D effects.

Identified cast members include Tom Clark as Lupin, Cliff Harrington as Jigen, Patricia Kobayashi as Fujiko, Frontier Enterprises owner William Ross as Goemon, and Greg Starr as Zenigata.

[6] The first widely distributed English dub was produced by Streamline Pictures and released in North America by Orion Home Video on VHS in 1995 under The Mystery of Mamo.

Directed by Streamline co-founder Carl Macek, the adaptation was written by Ardwight Chamberlain, who based his script off the Toho dub, but made various alterations to the original dialogue.

Discotek's release also includes the original Japanese audio, along with an isolated score track, as well as several essays and liner notes on the film.

Manga Mania reviewer Peter Lyle described the film as "a convoluted tale that plays like the adventures of James Bond, Don Juan and Charlie Chaplin all rolled into one" with "plenty of wry humour and slapstick".

[24] Rob Lineberger, writing for DVD Verdict, also agrees with the criticism of the final third, and despite repeated viewings, felt no closer to understanding the events.

Reflecting on the positives of the film, Lineberger highlights the characters of Jigen, Goemon and Fujiko as being more interesting than either Lupin or Mamo.

He described the structure of the film's story as "haphazard" and "a bit hard to get into", while praising the collection of "educational" extras and different English dubs on Discotek's release.

Praising Discotek Media's "fancy" DVD release, he described the film as "often held up as the example of how to write a Lupin story - it has unfolding drama within the core cast, a truly threatening villain, and an unusual dedication to mature storytelling.

[27] In an essay included with Discotek Media's release, ANN contributor Mike Toole highly praised The Mystery of Mamo in virtually every aspect, describing the film as "the absolute essence of Lupin III".

Toole concludes his essay by stating that "[m]ore than 30 years after its debut, [The Mystery of Mamo], with its heady mix of globe-trotting action, raciness, wild comedy, and hot jazz-funk music, is the original Lupin, the real deal.