Shuumatsu Nani Shitemasu ka? Isogashii desu ka? Sukutte Moratte Ii desu ka?

Japanese Title: 終末なにしてますか？忙しいですか？救ってもらっていいですか？

English Title: WorldEnd: What do you do at the end of the world? Are you busy? Will you save us?

Plot
It's been over 500 years since the human race almost went extinct at the hands of the fearsome and mysterious "Beasts". The surviving races now make their homes, towns, and cities up on floating islands in the sky to keep out of reach of all but the most mobile of Beasts. Only a group of young girls, dubbed the Leprechauns, can wield the ancient Dug Weapons needed to fend off invasions from those dangerous creatures. Into the peoples' unstable and fleeting lives, where a simple call to certain death could come at any moment, enters an unlikely character: a mysterious man who lost everything in his final battle five hundred years ago, and had awakened from a long, icy slumber. Unable to fight any longer, the man, Willem, becomes the father those kids never had, caring for and nurturing them even as he struggles to come to terms with his new life, in which he feels the pain of helplessly waiting for his loved ones to return home from battle that his 'Daughter' once felt for him so long ago. Together, Willem and the leprechauns gradually come to understand what family means and what is truly worth protecting in their lives.