Mira Yurizaki is a central character in the story, a highly advanced android created by Seira and Shidou Yurizaki. She was built to resemble a teenage girl with a slim frame, short green hair, and green eyes, and she possesses a metallic tail and robotic headgear that distinguish her from humans. Unlike other androids, Mira was constructed with complete brain components, granting her a personality that closely mirrors that of a young woman. She is peppy, kind, emotional, and has a sense of fashion, though she often insists that she is a normal girl despite her inhuman attributes. Her primary motivation stems from her deep sense of duty toward her creator, Shidou Yurizaki, whom she regards as her father. After hearing news of his death, she decides to help the reluctant collector Kyouma Mabuchi track down and retrieve illegal Coils, the dangerous devices that harness energy from Dimension W. She believes that her father considered these illegal Coils the key to an impending disaster, and she feels compelled to honor his final wishes.

In terms of abilities, Mira can override and hack into computer systems, use her metallic tail to directly interface with Coils for data extraction or manipulation, and detect dimensional distortions. She is confident in her capabilities but prefers not to engage in direct combat, instead relying on long-range projectiles or confrontation to resolve situations. She especially tries to avoid killing others. Her role in the story is that of a Collector, working alongside Kyouma as his partner at the Recovery House, where she becomes a member under the information broker Mary. Her relationship with Kyouma evolves from a master-servant dynamic into a genuine partnership based on mutual trust. Over the course of the narrative, Mira's journey focuses on her quest for identity and her struggle to understand the soul that her father claimed she possessed. It is later revealed that her body was originally created for Kyouma's deceased lover, Miyabi, whose surgery failed due to a malfunctioning Coil. Mira undergoes significant development, including a moment where her own Coil goes berserk and she encounters a vision of Shidou, who gives her a different Coil and tells her to live on and learn about human hearts. After this incident, when she witnesses Elizabeth crying at her father's death, Mira's Coil skips a beat, implying that she now possesses a heart similar to that of a human. Her development culminates in her transition from a fugitive machine into a vital protector of humanity, proving her humanity through her self-sacrificing actions.