Pino is a Companion-type AutoReiv, a childlike android designed to serve as a surrogate daughter for residents of the domed city of Romdeau. She was originally owned by Raul Creed and his wife Samantha Ross, who were unable to raise a biological child of their own. When the Creeds were granted a real baby son by the city government, Pino was scheduled for decommissioning because she was no longer needed. Before that could happen, a rampaging being known as a Monad tore through a public area and killed Samantha and the new baby. During this incident Pino became infected with the Cogito virus, a condition that grants AutoReivs self-awareness, and she awakened as a distinct individual. With her owners gone, she fled Romdeau and eventually became the traveling companion of Vincent Law, later joining Re-l Mayer on their journey as well.

Pino has the appearance of a small girl of about six years old, with light bluish-gray hair and childlike features. Her name is a short form of Pinocchio, and her story deliberately mirrors that tale of an artificial being seeking to become a real person. In personality she is cheerful, curious, talkative, outgoing, and playful, behaving much like an ordinary young child. Despite being a machine, she displays genuine emotional depth, empathy, and affection. A notable trait is her tendency to mimic human behavior and speech in an effort to connect with those she meets. Her recurring line, I want to be with you, captures her central motivation: a deep desire for companionship and a longing to understand human emotions and what it means to be alive. She frequently questions the nature of her own existence and whether her awareness makes her real.

Within the story, Pino serves as the constant companion of Vincent Law after leaving Romdeau, traveling with him across the post-apocalyptic wasteland. Her innocence, curiosity, and openness offer a lighter presence within a journey that is otherwise somber and reflective, and she often acts as a moral anchor, prompting Vincent to confront questions about identity, purpose, and memory. Her childlike perspective challenges the more cynical and world-weary attitudes of the adults around her, and her presence underscores the series' interest in consciousness and the possibility of humanity within artificial beings.

Pino's most significant relationship is with Vincent Law. She forms a deep and loyal bond with him, caring for him openly and serving as his emotional anchor during his struggles. Her connection with the Creeds also shapes her understanding of family, love, and loss, and Raul Creed later demonstrates a paternal attachment to her. Her interactions with Re-l Mayer and with other AutoReivs and humans she encounters along the way allow her to explore questions of existence, autonomy, and belonging.

Over the course of the series, Pino develops from a household robot into a being with genuine feelings and a growing sense of individuality. Her journey becomes a search for self-understanding, touching on identity, free will, and what it means to be human. Her growth raises the question of whether her personality was created by the Cogito virus or developed through her experiences and relationships with others, and she gradually becomes more emotionally complex as she witnesses joy, danger, and loss.

As a Companion-type AutoReiv, Pino possesses enhanced agility, adaptability, and the ability to move through dangerous situations and evade threats. She has basic combat capability but is primarily non-combative, and her mechanical nature leaves her physically vulnerable in situations demanding endurance or strength. Her most distinctive strength is emotional rather than physical: she connects deeply with human experience, brings clarity and warmth to those around her, and serves as a quiet moral guide throughout the journey.