Olympus no Yuubin Post

is a Japanese light novel series written by Tamao Ashino, with illustrations by Inumachi. The series began publication on March 10, 2017 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
It has been 200 years since human beings began full-scale settlement on Mars. There was an urban legend that has been handed down on this planet for some time.

Olympus postal post. The letter posted to the mailbox at the top of Mount Olympus, the largest volcano in the solar system, is said to be delivered by God to anyone, anywhere.

-Yes, even to heaven.

Ellis, a girl who works as a long-distance mail carrier on this star covered with red soil after repeated disasters and civil wars, asks for a job to deliver Kuro, a remodeled human being with a mechanical body, to the Olympus mailbox. Will be done. A long journey of 8,635km begins, aiming for the place called the place closest to heaven on Mars.