If you're looking for manga similar to Amanatsu, you might like these titles.
Earth after World War II. Rebuilding after the destruction has given rise to various vices. Disposers roam the cities cloaked in shadow and mystery. Kaede is a Disposer of SA rank, the highest level a disposer can reach. But he has to be in Central City, he must find the one who murdered his father...at any cost.
In the middle of a long war, scientists invented a drug that transforms the fear of death into pleasure, making it possible for school girls to fight alongside men. In this world of death, drugs, and rampant sex, one girl still dreams of true love. Will she find her romantic, happy ending?
On January 3rd, 2097, a collision with a celestial object basically destroyed human civilization. Seventy years later, human survivors are still living in space, unable to return to their home planet. Some humans, called "Divers" are able to project an avatar to the earth in order to salvage information from earth-based computer networks.Suzuro is a 14-year-old freelance diver of incredible skill, but only a C-rank due to age restrictions. She works in a salvage ship with her pilot Ginga, who keeps the ship out of flying debris while she's connected to earth, and her assistant Shimugi. It's not only space debris colliding with the ship that could kill Suzuro while diving, there are also dangers waiting on earth that could kill her, just by interacting with her avatar. Suzuro must be certain that the cases she takes are worth the danger!
Set in the near future. A boy wakes up from cold sleep and sees the ruins of a town covered in green. He journeys with a self-proclaimed sorcerer in order to find other humans.
A cosmic disaster changed the Earth forever, stripping away every last drop of color from the world. Mankind also changed: the familiar human face is almost forgotten in a world now populated wholly by mutants. Against the backdrop of a moody urban landscape, a lone wolf investigator named Avidia relies on both his wits and extraordinary gun to hunt down the world’s last hidden scraps of color. He soon crosses paths with a very special girl–one who just might hold the key to bringing back what the world has lost.
In a deserted post-apocalyptic metropolis riddled with a mysterious material a young girl is searching for any signs of life and supplies.