WorldEnd: What are you doing at the end of the world? Are you busy? Will you save us?

Five centuries after humanity was destroyed by mysterious creatures known as Beasts, the surviving races live on floating islands beyond most of the monsters' reach. Their defense depends on young Leprechaun girls able to wield ancient weapons against invading Beasts. Into their precarious lives comes Willem Kmetsch, the last surviving human, awakened after five hundred years. No longer able to fight as he once did, Willem instead becomes a caretaker to the girls, learning the helpless fear of waiting for loved ones to return from battle while they gradually form something resembling a family.