Kami-sama no Kaigogakari

From Yen Press: One strange day, roughly 20,000 otherworldly spaceships flew into stable orbit around the Earth. After six months with no contact from the mysterious crafts, in a certain Asian village, a young girl named Zihan discovers an old man who fell from the sky. Soon, many more elderly drifters in similar clothing begin popping up all over the world—their numbers surpassing two billion in total. What is the goal of these mysterious visitors? Find out in this adaptation of a story by popular Chinese sci-fi author Liu Cixin!