Tabi ni Deyou, Horobiyuku Sekai no Hate made.

is a Japanese light novel series written by Naoto Manya, with illustrations by Houmitsu. The series began publication on March 10, 2008 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
The world was gently perishing. "Humanity" was widespread, and humans disappeared one after another. People lose their names, their colors, and eventually their existence ... One Super Cub was running in such a world. Boys and girls are on board. Like everyone else, they suffered from "loss" and set out on a journey, abandoning their school and home. The aim is the end of the world. I don't know how to get there. But I don't want to stop traveling. I don't want to regret even if the day comes when each other disappears.

A story of a boy and a girl traveling with a diary in a world where records and memories have been lost.