Ende is one of two sisters working as operatives for the Berühren Corporation, deployed alongside Anne to capture Tetsuro Arahabaki. She possesses the ability to transform into a spider-like Extended form, wielding poisonous projectiles that sedate targets and disrupt Extended functions. This transformation is unstable, frequently causing her to lose control and enter a berserk state. Though formidable in combat, her berserk episodes require Anne's intervention to stabilize her and revert her to human form.

During their mission in the Kyusei Pit, Ende and Anne confront Tetsuro, who remotely controls Juzo Inui's body. Ende fires sedative rounds, incapacitating Tetsuro and disabling his Harmony device. When their superior, Hugh Cunningham, deems this a failure, he shoots Ende with drugged bullets to deliberately trigger her berserk state. In her rampage, Ende mortally wounds Anne. Anne's final act is pleading with the weakened Tetsuro to save Ende. Juzo halts Ende's rampage by allowing Tetsuro to fire his head-gun, destroying her extensions.

Ende's relationship with Anne is central; Anne serves as her handler and emotional anchor, capable of calming her post-berserk. Ende expresses reluctance to harm others, particularly children. She views Berühren as her only home despite not being a prisoner, highlighting her vulnerability within the corporation's structure. Anne's death leaves Ende without her primary source of stability.

After the incident, Ende survives but remains in a vegetative state due to neurological damage. She is placed under the care of Mary Steinberg, who develops countermeasures for the poisonous program affecting Ende and other Extended children. Ende's condition acts as a catalyst for Mary's efforts to aid Berühren's victims. Her persistent catatonic state symbolizes the consequences of the corporation's manipulation of Extended individuals.