Arve Rezzle: Kikaijikake no Yousei-tachi

Remu Mikage is speaking with his sister Shiki when she reveals that the voice and image he sees are artificial. To study more efficiently, she has uploaded her consciousness through neural-linked nanomachines while her physical body is stored elsewhere. Then the catastrophe known as the Early Rapture strikes, leaving uploaded minds dead or comatose.

Remu later finds Shiki standing at her apartment despite everything that should make her presence impossible. She remembers neither him nor her past, and violent researchers are already pursuing her. As the siblings flee, Shiki discovers that she can manipulate nanomachines, a power that may explain why she survived and why others are so determined to capture her.