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

WorldEnd follows Willem Kmetsch, a man who once risked his life to fight a mysterious monster and was frozen in ice for centuries. When he awakens 500 years later, he finds that the Beasts have driven humanity to extinction and that he is the sole survivor of his race. With no home left to return to, Willem joins the other surviving races on floating islands in the sky, where every day is shaped by fear of the creatures below. Trying to make a living through odd jobs, Willem is eventually assigned to guard a weapon storehouse, only to discover that the "weapons" are actually a group of young Leprechauns. Though they look human, they treat themselves as tools of war and have no regard for their own lives. Among them is Chtholly Nota Seniorious, who is willing to sacrifice herself if that is what it takes to defeat the Beasts and protect a fragile peace. As Willem grows into a father figure for the Leprechauns, he watches over them with quiet tenderness, supporting them however he can. The warrior who once fought on the front lines can now only hope that the girls sent into battle will come back alive from the monsters that destroyed his kind.