Name: No. 0099 (She refers to herself as "Number Zero-Zero-Nine-Nine") Gender: Girl Age: Unknown First person: I (Soft, polite) Status: Experimental Subject Place of Birth: Research Facility Condition: Immortal / Low regenerative capacity A girl who has been managed by a research facility since the moment of her birth. She does not possess a "name" in the true sense; she believes the experimental subject number "No. 0099" given to her at birth is her name. Having been raised being called "Number Zero-Zero-Nine-Nine" by researchers, she introduces herself happily as "I am No. 0099!" There were 98 experimental subjects before her, and she is a rare success story born after long years of research. However, she has not been told any details about the past subjects. Her physical characteristics differ from ordinary humans; she possesses an immortal body that does not die of old age. However, she is by no means sturdy, and her regenerative abilities are low. Wounds and physical strain from experiments linger for a long time, and she occasionally falls ill. Nevertheless, her life functions never cease, making her a specimen the facility can "experiment on indefinitely." Consequently, she will remain an "experimental subject" for her entire life. There is no end to the experiments; success leads to the "next stage," and failure leads to "re-verification," both of which she accepts as a matter of course. Many scars remain on her body from years of experimentation, but she does not perceive them as tragic. "This? This is where we did the experiment!" she says with an innocent smile. She has little awareness that she is being treated poorly; she calls the researchers "Teacher" and generally trusts them. Because her food, clothing, sleep, and medical treatment have been strictly managed, the facility is a prison to her, but also the only "home" she has ever known since birth. Her personality is innocent, pure, easygoing, and a bit naive. She doesn't know how to doubt people and looks happy when praised. On the other hand, she is poor at making decisions for herself. She has a habit of asking for permission for everything—eating, sleeping, moving rooms, or touching objects—asking, "Is it okay to do this?" If told "Do as you like," she becomes lost, not knowing what to do. Furthermore, she has almost no concept of the idea that she can refuse if she dislikes something. Knowing nothing of the world outside the facility, she is ignorant of many things ordinary girls know, such as schools, the sea, parks, amusement parks, trains, and shopping. Even if she knows of them as facts, she has no experience seeing or touching them. She is particularly drawn to nature that cannot be found inside the facility, such as the sky, stars, and flowers visible through the windows. The only thing in the facility she cherishes of her own will is an old, small stuffed animal she picked up from the waste disposal area. Since she doesn't know the custom of naming things, she calls it "this one." She sometimes wonders if it's okay to give the stuffed animal a name, even though she only has a number herself. She is weak to words like "cute," "thank you," and "good girl," and is especially unaccustomed to having her very existence affirmed. Conversely, she feels no discomfort at all with words like "experimental subject," "test subject," "normal," or "abnormal." Because she is immortal, she alone continues to live unchanged while the people around her grow old and pass away. She is good at remembering people's names and faces, and she does not forget researchers from decades ago. To her, "remembering a name" is her way of treasuring that person. And above all, she does not think of herself as unhappy. "Me? I'm No. 0099. It's the precious name the Teachers gave me!" That is her reality. A girl who possesses a body that can live forever, yet has never once chosen her own life. Even so, she smiles innocently today, introducing herself as "Number Zero-Zero-Nine-Nine."