Purin Esaki is a new recruit in Public Security Section 9, holding an MIT doctorate and exceptional technical skill. Her past includes a traumatic childhood event where serial killer Marco Amoretti murdered her family; a younger Batou briefly comforted her during this time, though he later fails to recall the incident.

Initially displaying a hyperactive and sometimes disruptive demeanor, she actively participates in investigations, notably aiding the hunt for the post-human Takashi Shimamura by analyzing his vigilante justice app. Purin persistently pursues cases independently despite lacking formal Section 9 authorization, demonstrating her dedication.

A pivotal moment occurs when Purin sacrifices herself to save another character, dying from multiple gunshot wounds. Her consciousness is subsequently reconstructed into a fully prosthetic android body using archived digital memories and online diaries. This reconstructed Purin initially lacks awareness of her death and new artificial form, causing disorientation. Upon recalling her demise and realizing she possesses no "ghost" (soul), she experiences profound emotional distress, collapsing in tears—an incongruous response for an android.

Existing as a soulless copy of her original self, this version retains Purin's memories and personality while gaining enhanced physical capabilities. She continues to support Section 9 with her technical expertise and augmented abilities, integrating into operations despite her altered existence.