Miki Kouzuki is the mother of the protagonist Miyu Kouzuki and a central figure in the setup of the story. Her background is defined by a lifelong passion for outer space; she is an astronaut who, along with her husband Yu, is recruited by NASA at the beginning of the series. This career opportunity requires the family to relocate to the United States, and Miki arranges for her daughter to stay with the Saionji family, lifelong friends, while she and Yu are away. Miki’s personality is characterized by her intense fascination with anything related to space, a trait that drives her professional ambitions. She is a caring and responsible parent, though her absence for much of the narrative means she is primarily seen in early episodes or through recollections. Her motivations are rooted in two childhood dreams: to have a beautiful daughter and to become an astronaut, both of which she achieves. She shares a close friendship with Kanata’s late mother, Hitomi Saionji, a bond that predates the events of the story. In the series, Miki’s role is largely expository, establishing the circumstances that leave Miyu and Kanata to live together and care for the alien baby Ruu. She does not possess any supernatural abilities; her notable skill is her profession as an astronaut, which reflects her dedication and expertise in space science. Her character does not undergo significant development over the course of the anime, as she remains off-screen for most of the story, but her influence is felt through the arrangements she makes and the aspirations she instills in her daughter.