Five hundred years have passed since humans were eradicated by fearsome and mysterious creatures known as "Beasts." The surviving species now inhabit floating islands high above ground level, out of reach for all but agile Beasts. Only a handful of young girls, the Leprechauns, possess ancient weapons capable of warding off attacks from these beasts. Amidst their unstable and fleeting lives, where danger lurks at any moment, enters an unexpected figure: a man who lost everything in his final battle five hundred years ago, awakening as the last living human to return from a long, icy slumber. Unable to continue fighting, Willem becomes the father that none of them ever had. Despite battling with grief over leaving behind loved ones, he cherishes and nurtures the girls, struggling to reconcile himself with his new existence where waiting for their return feels like an unbearable burden shared by "Daughter" once felt for him a long time ago. Together, Willem and the Leprechauns gradually discover what family truly means and the things that are worth protecting.
Willem Kmetsch, an outcast, finds a new lease on life as the caretaker of ext...