Kamisama no Kaigogakari

One mysterious day, over twenty thousand otherworldly spaceships settle into stable orbit around Earth. Six months later, in a certain Asian village, a young girl named Zhihan discovers an old man who fell from the sky...but the strangeness doesn't end there. Soon, many more elderly drifters in peculiar outfits begin descending all over the world, claiming they created human civilization. Now it's humanity's turn to take care of their Progenitors—but as Zhihan will soon learn, accepting God into your home isn't such a simple matter...

(Source: Yen Press)