Laura debuts as a human assassin employed by the entity Apos to kill Rin Asougi. Unaware of Rin's immortality during their 1990 clash, Laura sustains fatal wounds, including the loss of an eye. To save her life, Apos administers a Time Fruit, granting her immortality. The regeneration proves flawed, leaving permanent damage like the unrepaired eye injury. This incomplete healing later necessitates cybernetic augmentation, rendering her an immortal cyborg.

For decades afterward, Laura relentlessly hunts Rin, attacking at every chance. Her pursuit shifts from professional duty to a personal obsession fueled by pride and vengeance for her injuries. Her cybernetic form maintains her combat effectiveness despite her impairments.

A pivotal betrayal occurs when Apos sends Angels to eliminate Laura during a crucial battle against Rin. In retaliation, Laura abandons Apos and aids Rin's allies, Mimi and Mishio Maeno, guiding them to Yggdrasil's root system, the source of the Time Fruits.

In her final act, as Apos faces absorption into Yggdrasil, Laura asks Rin to retrieve her Time Fruit and force Apos to consume it, ensuring he suffers the same perpetual torment she endured. Even after her defeat reduces her to a disembodied cybernetic head, her intense hatred for Rin persists, expressed as a desire to spit on her.