With aims to one day reach out into the stars, humanity has colonized all the planets of the solar system. This story of young high school hopefuls is set in Fourth Tokyo in a Japanese Martian prefecture. Iris Shirasaki is a third year student/aspiring test pilot. Mizuki Sera is her peer/mechanic and Mizuki's brother Kaito is their homeroom teacher and the young director of the program developing their talents.—Crunchyroll