The Color of the End 4

Volume 4 of the manga series The Color of the End by Haruo Iwamune – German-language edition.

Decades after an alien miasma wiped out humanity, a young girl named Saya roams the ruins of a collapsed city on her own. Her job is to purge the debris of the miasma and make the land livable again, even though she has never met a single survivor. Along the way she uncovers traces of the past and has to ask herself who she is really doing this work for.