Sayla Mass, born Artesia Som Deikun on September 12, Universal Century 0062, was the daughter of philosopher-politician Zeon Zum Deikun and younger sister to Casval Rem Deikun. Following her father's assassination in UC 0068, she and Casval were smuggled to Earth under Jimba Ral's protection, escaping persecution by the Zabi family. Adopted by aristocrat Don Teabolo Mass, she assumed the name Sayla Mass, residing in Spain before relocating to the Texas Colony. Unlike her brother's vengeful resentment toward the Zabis, she grew up without such intentions, focusing on medical studies at Side 7. The One Year War erupted, and Zeon's attack on Side 7 forced her evacuation onto the SCV-70 White Base. While searching for survivors, she encountered the masked Char Aznable, recognizing him as her brother Casval. Aboard White Base, she served initially as a communications officer and de facto medical officer, displaying professionalism and compassion. Her piloting skills emerged when she commandeered the RX-78-2 Gundam to gather information on Char, resulting in solitary confinement but leading to her role as a backup Gundam pilot. She later became the primary pilot of the FF-X7-Bst Core Booster, demonstrating growing combat effectiveness and nascent Newtype abilities in battle. Her identity as Artesia surfaced when Ramba Ral, son of her childhood protector Jimba Ral, boarded White Base and recognized her. Their reunion ended tragically with Ramba fatally wounded and committing suicide to protect her. This event, coupled with the deaths of comrades like Ryu Jose and Matilda Ajan, deeply affected her. Throughout the conflict, she attempted reconciliation with Char, meeting him at Jaburo and Texas Colony. Char, seeking to shield her from the war, sent her gold bars to fund a new life; she distributed the gold among the White Base crew, whom she had come to view as family. During the war's final stages, her intervention in a skirmish inadvertently caused Lalah Sune's death when Char hesitated to attack her Core Booster. At the Battle of A Baoa Qu, she intervened in Char and Amuro Ray's sword fight, prompting Char to abandon the duel to pursue Kycilia Zabi. He urged Sayla to escape with Amuro and "have a good life," acknowledging their bond. The novelization depicts a romantic relationship between Sayla and Amuro, including intimate moments and a psychic declaration of love before Amuro's death. After the war, she completed her medical training and founded the Yumi Foundation to aid war orphans. During the Gryps Conflict, she listened melancholically to Char's speech as Quattro Bajeena. In the First Neo Zeon War, she rescued Judau Ashta's sister Leina and later informed Bright Noa that Char's ambitions necessitated his death for peace. By UC 0096, she briefly returned to piloting, supporting military operations in a Core Booster. Her identity as Artesia was publicly revealed during the Laplace Incident, cementing her legacy.