Driven by the ambition to eventually reach the stars, humanity has colonized every planet in the solar system. This narrative follows young high school students and takes place in Fourth Tokyo, located within a Japanese prefecture on Mars. Iris Shirasaki is a third-year student and aspiring test pilot. Mizuki Sera is her classmate and mechanic, while Mizuki's brother, Kaito, serves as their homeroom teacher and the young director of the program cultivating their abilities.