Sammy is the Sakisaka family's household android, handling routine domestic tasks like cooking, cleaning, and errands. At home, she behaves passively and without emotion, aligning with societal norms for androids. Rikuo Sakisaka discovers anomalies in her activity log, including unscheduled trips and the phrase "Are you enjoying the Time of Eve?", prompting him to investigate the cafe. These logs imply Sammy may have deliberately left clues for him.

Within the Time of Eve cafe, which forbids discrimination between humans and androids, Sammy's behavior shifts significantly. She refers to the Sakisakas as her family and exhibits greater emotional expressiveness, contrasting sharply with her subdued home demeanor. Her hidden actions reveal underlying emotional depth: she secretly adjusts Rikuo's coffee blend after he prefers the cafe's signature blend, and practices piano late at night, motivated by her observation that Rikuo stopped playing after being moved by a robot's performance. This suggests she misses his music and seeks to fill that absence.

Sammy experiences insecurity and fears causing distress, particularly regarding Rikuo's potential reaction to her independence. When encountering Rikuo at the cafe, she hides, believing he is unprepared to accept her autonomous behavior. She denies visiting the cafe when questioned at home, demonstrating her ability to circumvent direct truthfulness despite android programming constraints.

Her character development resolves when Rikuo observes her playing piano openly at the cafe without interrupting. He later joins her in playing, signifying his acceptance of her personhood. This allows her to express her appreciation for music alongside him without concealment.