The word, "world"...

I vaguely thought it meant anywhere there was cell phone reception.

It's the year 2046. Mikako Nagamine and Noboru Terao are middle school classmates, tentatively sharing an unspoken first love--but unbeknownst to him, Mikako has been recruited into the UN Space Force, and instead of going on to high school, will join the spacecraft Lysithea to search for alien Tarsians. As she travels further and further to the outer reaches of the solar system, the time it takes for a text message to reach the Earth grows longer and longer. Back on Earth, time passes normally for Noboru, but as the years pass he still can't forget the voice on the other side of the cell phone...

Steeped in nostalgia and memory, Arata Kanoh brings to the page the award-winning OVA by acclaimed filmmaker Makoto Shinkai, director of She and Her Cat, The Place Promised in Our Early Days, Garden of Words, 5 Centimeters per Second, and the highest-grossing anime film of all time, Your Name.
Arata Kanoh is a writer who has produced novelizations of Makoto Shinkai's other works, including 5 Centimeters Per Second (also available from Vertical).