Naoko is the barista of a unique cafe fostering equality between humans and androids. She meticulously runs the establishment, strictly enforcing its core rule against discrimination. To maintain this environment, she ensures androids conceal their status rings and employs measures like automatically locking the door for two minutes after patrons leave, preventing anyone from discovering others' identities.

Initially, her own nature is ambiguous; patrons and viewers remain uncertain whether she is human or android, partly due to her occasional uncertainty handling cafe situations. This ambiguity persists through much of the narrative. It is later revealed she is human and was the five-year-old child injured in the Tokisaka Incident eight years prior. This event involved the Ethics Committee, an organization monitoring android-human interactions, and left her physically affected.

Her personal history is deeply connected to broader societal tensions. She is the daughter of Shiotsuki, the original creator of androids. In a post-credits scene, she returns home and speaks to him, expressing optimism about the growing harmony within the cafe. She tells Shiotsuki that his "children" (the androids) are beginning to laugh alongside humans there, suggesting this camaraderie will eventually extend beyond its walls. This moment highlights her role connecting her father's creations to human society.