Mamo is a central figure in the Lupin III franchise and appears as the hidden mastermind behind the events of Lupin the IIIrd: The Immortal Bloodline. First introduced as the primary antagonist in the 1978 film The Mystery of Mamo, also known as Lupin vs. the Clone, Mamo is portrayed as an ancient being of immense knowledge and wealth who has existed for thousands of years. His primary motivation is the pursuit of eternal life, and he has spent millennia manipulating major historical events from behind the scenes in service of this goal. In The Immortal Bloodline, which serves as a prequel to The Mystery of Mamo, Mamo is revealed to be the architect of the film's central conflict. He created the immortal entity known as Muom from the blood of another immortal being, and he orchestrates the series of attacks on Lupin and his allies, luring them to a mysterious uncharted island. Throughout the film, Mamo operates as a shadowy puppeteer, using Muom as his direct agent to confront Lupin's crew. His role in the story is that of the ultimate antagonist, a schemer whose centuries-old plans set the entire plot in motion. Mamo's key relationships include his creation Muom, whom he controls, and his long-standing rivalry with Arsène Lupin III, a conflict that spans multiple films and timelines. He has also appeared in the OVA Daisuke Jigen's Gravestone, where his presence hints at his larger schemes. In terms of character development, The Immortal Bloodline deepens Mamo's history by showing him as a manipulative force who has been pulling strings across centuries, making him a more complex and entrenched adversary than a simple one-film villain. His notable abilities include his vast accumulated knowledge, his understanding of immortality and genetic manipulation, his ability to create and control other beings like Muom, and his capacity to erase evidence of his existence, as seen when he destroys the island and all records of Lupin's lineage at the film's conclusion. Mamo is defined by his calculating intellect, his obsession with eternal life, and his willingness to manipulate both people and events on a global scale to achieve his ends.