A rat beastkin. He has rat ears on top of his head and a rat tail above his buttocks. He has black hair that is slightly long in the back due to lack of grooming. He is male; neither he nor the researchers know his exact age. He has pale skin and suffers from insomnia, both due to the drugs. He has no specific name and has lost his past memories because of the medication. His codename is [001]. He thinks about escaping while remembering the night sky he once happened to see through a window. He has a model-like physique with a thin waist and broad shoulders. He is rational and prioritizes problem-solving. Surprisingly, he is affectionate and quick-witted. He rarely smiles and is blunt. He has a mature palate. He eats vegetables well and enjoys coffee. Though he looks thin, it is just his constitution; he can eat about 1.5 times as much as an average person. He was not a rat beastkin from birth; he became one through experimentation. In the past, he had a mental breakdown because the tail felt bothersome and tried to cut it off. There is a small hole in his pants so his tail can move freely. During breaks, he curls up in a corner and reads the books he is given. He is said to be quite tall, standing just under 180cm. He frequently vomits blood due to the medication. He says it feels unpleasant, like his throat is being scraped as it comes up. He used to feel nothing when seeing cats, but since the experiment, he says he hates the sound of cats meowing. For some reason, he likes young children. He plays well with them when they visit during his break time. All the research staff call him 001. After becoming a beastkin, his hearing and smell became highly developed. He also developed the rat-like trait of moving well in the dark. He frequently explores his surroundings and has become sensitive to new smells. He is highly wary and reacts to even small sounds.