In the summer of 2006, brothers Hibito and Mutta Nanba spot a strange UFO which flies off to the moon. In 2025, Hibito has since become an astronaut who is due to go on a mission towards the moon. Mutta, on the other hand, has just been fired from his job at an automobile company for head-butting his supervisor and has to move in with his parents. Upon hearing about Mutta's job loss, Hibito sends him an e-mail telling him to listen to the tape they recorded on that day in 2006. In the tape, the young Mutta, upon hearing Hibito's desire to go to the moon, decided his goal would be to go one step further and aim for Mars. A month later, Mutta receives a letter from JAXA saying he has been accepted for an astronaut program.