Manon is an ancient alien being who arrived on Earth during the Ice Age, approximately thirty thousand years before the main events of the series. Upon reaching the planet, Manon entered a deep hibernation within Austral Island, intending to awaken at a later time when an intelligent native species had emerged. Manon belonged to a race that actively sought out other forms of intelligent life across the cosmos, even though they understood that such contact carried the risk of conflict.

Manon is characterized by a strong sense of duty and adherence to a strict code of conduct. This code led to a fundamental disagreement with another member of the same alien race, Zenon, who advocated protecting those of their kind that chose to live among humanity. Manon, by contrast, believed that any being who had broken the code by integrating with humans should be eliminated, regardless of whether they were unarmed. Despite this rigid stance, Manon also demonstrates a capacity for compassion and a somber understanding of the tragic nature of their mission. The character shows a willingness to make difficult decisions for the greater good, as when Manon asks the protagonist Yuu Tagami to remain with the giant robot Gorg for the sake of his lost family.

In the story, Manon acts as the leader overseeing the hibernating inhabitants of Austral Island, waiting for the moment when they would be awakened and their robotic guardians had secured the planet for their return. Manon’s role comes into direct conflict with the human characters who seek to uncover the secrets of the island and protect it from corporate exploitation. As the narrative progresses, Manon helps to prevent a global nuclear launch plan orchestrated by the organization GAIL. After this resolution, Manon sinks into the sea alongside the robot Gorg and enters another long slumber, symbolically closing their involvement with humanity.

Key relationships include the alien counterpart Zenon, whose opposing philosophy creates a central ideological conflict. Manon also interacts with Yuu Tagami, whom Manon ultimately entrusts with the future of Gorg and the protection of the island’s legacy. The relationship with the giant robot Gorg is one of command and purpose, as Manon is linked to the island’s defense systems and the activation of its mecha.

Manon’s notable abilities include the capacity to hibernate for tens of thousands of years, control over the island’s advanced technology and robotic guardians, and the authority to initiate or halt planetary-scale events such as the Austral Obliteration Plan. These abilities stem from Manon’s extraterrestrial origins and their role as a custodian of a long‑dormant civilization.