A Quick Question on Chikyuu no Houkago

Have anybody read this manga called, "Chikyuu no Houkago"? It's about mankind mostly got destroyed by unknown dark monsters called Phantoms, leaving a few to struggle on survivor. Four of them are the last hope for the humans. These four survivors along with another one: Masashi, two teenage girls, the shy Sanae, the bolder Yaeko, and a little girl called Anna. Together, they began to see new mysterious behind the Phantoms and their objectives and questioned how they came to Earth and why the monsters wiped out most of mankind.