Princess Emeralda hails from the Sanborn duchy and stands central to "Cobra The Animation: Time Drive," which delves into her past. As princess, she spearheads a rebellion against the oppressive reign of King Giros and his forces, including bodyguard Manidou, placing her at the core of her realm's political conflict.

When Cobra accidentally travels back to her time, Emeralda encounters both his past and future selves. Her initial alliance with the past Cobra involves fighting shared enemies, fostering trust and collaboration. This trust blossoms into romantic feelings, significantly shaped by her exposure to the future Cobra's heroism, though she remains unaware of the time traveler's true identity during their early encounters.

A pivotal moment arrives when Emeralda suffers a fatal injury. To save her life and ensure Cobra's survival, she undergoes a transformation, transferring her consciousness into a robotic body. This conscious choice, driven by loyalty and a desire to protect Cobra, transforms her from human princess into the artificial Armaroid Lady, Cobra's future cyborg companion.

This sacrifice definitively links her past identity as Emeralda to her future existence as Lady. The narrative explicitly establishes her as Lady's human origin, revealing the foundation of their partnership and its emotional core. It concludes by directly connecting her past choices and experiences to her future role, providing her definitive backstory.