Queen Emeraldas, born Emeraldas, commands the warship *Queen Emeraldas* as a La Metalian space pirate. Descended from Queen Promethium of the Machine Empire and Dr. Ban, she shares blood with twin sister Maetel and cousin Phantom F. Harlock III. A scar etched on her left cheek during a clash with Illumidas officer Murigson in *Arcadia of My Youth* marks her refusal of Machine Body immortality, a testament to her embrace of human frailty. Her bond with human engineer Tochiro Oyama transitioned from indifference to profound mutual respect and love, culminating in the birth of their daughter, Mayu Oyama. Grief-stricken after Tochiro’s death, Emeraldas withdrew emotionally, preserving his legacy by entrusting his Cosmo Dragoon firearm to Hiroshi Umino, a determined stowaway echoing Tochiro’s spirit. Guided by a stringent honor code, she selectively targets oppressors like the Arfressian Empire and Illumidas, minimizing collateral damage. Her ethos mirrors Captain Harlock’s, with whom she shares decades of camaraderie forged in defiance of galactic subjugation. Renowned for gravity saber prowess and sharpshooting, she navigates solitude, favoring ephemeral alliances over lasting ties. Estranged from her mother over Machine Empire policies, Emeraldas clashed initially with Maetel due to conflicting ideals, though their rivalry later softened into reluctant acknowledgment of shared lineage. The Tokarga crisis in *Arcadia of My Youth* proved pivotal, uniting her with Harlock and Tochiro against Illumidas occupation—a struggle cementing her identity as a freedom fighter. In later chronicles like the *Queen Emeraldas* OVA, wanderlust and grief propel her across desert worlds, where she disrupts despots such as Queen Baraluda. Though revered as a symbol of resistance by oppressed colonies, she avoids lingering entanglements. Her legacy intertwines with galactic mythology, from navigating Count Mecha’s Time Castle corridors to insights on the Arcadia’s origins, underscoring her pervasive influence throughout the Leijiverse.