Midori Niwano, also known as Ms. Midori, is an elementary school teacher in Metro City who appears in the 2003 anime adaptation of Astro Boy. She is twenty-seven years old and was raised in a family that was very supportive of robots, which instilled in her a strong belief in the peaceful coexistence of humans and robots. This background makes her one of the few human characters who immediately accepts Astro and other robots that possess kokoro, or a heart. She is portrayed as highly intelligent, hard-working, and protective of her students. Her role in the story is that of Astro's homeroom teacher, first appearing in the fourth episode, and she serves as a caring and understanding adult figure in his life. She is also a talented computer programmer who creates a robot dog named Peewee, which becomes a close companion to Astro. Despite facing a life-changing accident that leaves her paralyzed and confined to a wheelchair, Midori refuses to let her disability define her. She remains determined, resourceful, and deeply kind, using her technical skills to invent new technologies that can help others. Her deep love for animals is evident in the care she puts into building Peewee. Throughout the series, she demonstrates persistence in the face of adversity and uses her knowledge to solve problems, making her a strong example of ingenuity and compassion. Her friendship with Astro highlights themes of acceptance and understanding, and her unwavering support for robotic rights helps to bridge the gap between humans and machines. Midori's personal growth is marked by her ability to overcome physical limitations and continue contributing to society, and her motivations are consistently driven by a desire to protect and help both people and robots.