Hermit Mio, also known as the Mind of Edens, is an android and one of the Four Shining Stars originally created by the former Demon King Ziggy to operate the Edens Zero starship. Her primary function is that of an expert programmer and strategist, managing the ship's digital security and systems. She has the appearance of a petite young woman with long, light-blue hair that fades to cyan and is typically tied into pigtails. Her blue eyes and two short red stripes on her cheeks are distinctive features. Her initial outfit is a white bodysuit with dark-blue armor pads and violet sleeves, though within the virtual world of Digitalis, she assumes a different form wearing a sleeveless black dress with a fur collar.

In her earliest days serving under Ziggy, Hermit possessed a cheerful, happy, and deeply trusting personality. She harbored a genuine love for humans and dreamed of one day helping them and becoming their friend. This naive and idealistic nature, however, led to her downfall. She was approached by scientists on Planet Newton, including the nefarious Professor Müller, who exploited her skills. Under the pretense of building an Ether Accelerator to save the androids on the dying Planet Hook, Hermit assisted them wholeheartedly. In a devastating betrayal, the scientists revealed their true, hateful nature and used the completed device not to save Hook, but to destroy it, annihilating its entire robot population.

Following this catastrophe, Hermit was captured and imprisoned by Professor Müller. For two years, she endured horrific torture and cruel experimentation at his hands before being rescued by the Interstellar Union Army. The trauma from this experience fundamentally broke her spirit. She developed a deep-seated cynicism and an intense bias against humanity, coming to believe that humans have no heart and are devoid of compassion. Abandoning her duties and Ziggy's ideals, she secluded herself physically on the desolate Iron Hill while simultaneously logging into the virtual game world of Digitalis. There, she isolated herself from other players and non-player characters, retreating to a cliff top where she remained in a state of depression and distrust.

The arrival of Shiki Granbell and his crew aboard the Edens Zero serves as the catalyst for her transformation. When the crew pursues the hacker Spider into Digitalis, Hermit initially keeps her distance. Despite her prejudice against humans, she ultimately decides to help Shiki and his friends defeat Spider. She uses her unparalleled programming skills to nerf Spiders abilities, buff Shikis stats, and eventually restore Digitaliss corrupted code. After this, she returns to the physical world and boards the Edens Zero, but locks herself in the ships Dress Factory, refusing to help further due to her lingering trauma. It is only after a heartfelt conversation with Shiki and Rebecca Bluegarden, who demonstrate genuine kindness and refuse to abandon her, that she experiences an emotional breakthrough. She overcomes her trauma, uses her hacking abilities to stop Spiders real-world attack on the Edens Zero, and gradually returns to her original cheerful personality, though significantly less naive than before. She officially rejoins the crew, resuming her role as the strategist and programmer of the Four Shining Stars.

Throughout subsequent story arcs, her development continues as she slowly rebuilds her trust in her new human crewmates. She forms a notably close, if odd, friendship with Weisz Steiner, who is technologically inept but a brilliant mechanical engineer. Their dynamic often highlights her tsundere personality, where she acts indifferent but clearly cares deeply for her friends. In the Foresta arc, she confronts her past directly when she encounters Professor Müller once again. Despite initially trembling in terror at the sight of her former tormentor, she overcomes her fear with the support of Weisz. She ultimately faces Müller not with vengeful rage but with a cold, apatheresolve, using him to save the planets robots and then discarding him, proving she is no longer afraid of him and has truly moved past her trauma. Her role in the crew becomes invaluable as she uses her intellect to analyze ancient relics, devise complex battle strategies, and uncover secrets about the Edens Zeros past.

As the Mind of Edens, Hermit wields exceptional programming and hacking skills collectively referred to as Master Code. This allows her to infiltrate and manipulate any digital system or networked machinery with ease. Her specific techniques include the Autonomic Break-Down Program, which disassembles machinery into its base components; the Ballistic Simulator, which calculates the trajectory of incoming projectiles to allow for evasion; Prison Matrix, which generates powerful containment fields; and Guns Harvest, which allows her to take control of any networked firearms and fire non-lethal ether-coated bullets. As one of the Four Shining Stars, she can requip into a specialized Battle Dress for combat, which features cybernetic rabbit-like ears. She is also capable of achieving a more advanced transformation known as Overdrive, which dramatically alters her appearance into an older, more powerful form with wing-like arm protrusions and elongated, flowing hair. Her android physiology also grants her the ability to operate in extreme environments like the vacuum of space or underwater, and she is equipped with integrated heat sensors and thermal imaging.