Hoshi No Koe

Noboru and Mikako, both junior high school students, were close classmates — until the summer of their third year, when Mikako was chosen to join the UN Space Army’s elite team. Separated between Earth and space, the only thing connecting them now is text messages sent via their mobile phones…

But as Mikako’s spaceship travels farther from Earth, the time it takes for her messages to reach Noboru grows longer. Though separated by vast time and distance, their feelings for each other remain — and slowly begin to change…

This is the novel adaptation of Voices of a Distant Star, Makoto Shinkai’s first commercial work, who would later go on to direct Your Name.