The Mystery of Mamo, also known as The Secret of Mamo, is a 1978 Japanese animated science fiction action comedy film; it is the first animated film of the Lupin III franchise created by manga author Monkey Punch. The film was originally released in Japan as Lupin III (ルパン三世, Rupan Sansei) but was later retitled to Lupin III: Lupin vs. the Clone (ルパン三世 ルパンVS複製人間 (クローン), Rupan Sansei: Rupan tai Kurōn) to differentiate it from other elements of the franchise. Directed by Sōji Yoshikawa from a screenplay by Yoshikawa and cult pink film screenwriter Atsushi Yamatoya, the film was produced by animation studio Tokyo Movie Shinsha and distributed by Toho. The film's plot follows master thief Arsène Lupin III, who attempts to foil Mamo ― a wealthy and powerful recluse seeking immortality ― while t