Fragile - Sayonara Tsuki no Haikyo

The story is set in a post-apocalyptic near future Earth that has lost its light and is covered in a dense fog. Almost all the world's population has vanished, and the cities have been left abandoned. After his "grandfather" died, Seto, a young boy, decided to set out in search for other humans. (Source: Wikipedia)

This manga is a continuation of the role-playing video game for the Nintendo Wii called Fragile Dreams: Sayonara Tsuki no Haikyo developed in 2009 by Namco Bandai Games in cooperation with Tri-Crescendo.