Prior to becoming a Números, Apacci was a deer-like Hollow. Apacci first met Harribel back when she was still an Adjuchas. Harribel saved her from another Hollow that was about to devour her. She then followed Harribel back to her base where she met Franceska Mila Rose and Cyan Sung-Sun. There, Harribel invited Apacci to join their group, but Apacci was resistant to the idea of working in a team. However, she reluctantly agrees. Sometime later, the three Apacci, Mila Rose, and Sung-Sun chase down another Hollow. When Harribel instructs them to allow it to escape, Apacci questions why. Harribel explains that she does not want to get stronger by devouring other Hollows and that if she cannot defeat them alone, she will defeat them together with others.
Harribel saves Apacci.
When Harribel was confronted by Baraggan's court, Apacci witnessed Harribel cutting down one of Baraggan's Hollows and rejecting Baraggan's request to serve him or leave. Sometime later, the same Hollow, now an Arrancar, entered their lair and attacked the group. Harribel appeared and ordered Apacci and the others to run while she fought the Arrancar. Apacci was reluctant to abandon Harribel and convinced Mila Rose and Sung-Sun that they must help their master. They returned to assist Harribel, but were quickly beaten by the Arrancar. As Harribel was about to be killed, Sōsuke Aizen appeared and dispatched the Arrancar.