Five hundred years have passed since the mighty and enigmatic 'Beasts' ravaged humanity. Now, the surviving races inhabit floating islands high above the ground, out of reach of all but the most agile of the Beasts. However, despite this apparent refuge, a dark secret looms over them - Regul Aire.
The Leprechauns, a band of young maidens, are the only wielders of ancient weaponry skilled in defending against the invading creatures. Although constantly facing danger, they persevere. Amid their precarious and fleeting existence, an unexpected visitor changes their lives - a young man cryogenically frozen for half a millennium after losing everything in the final battle, the last surviving human.
While no longer able to fight, Willem takes on the role of a fatherly figure for the girls, tending to their needs and nurturing them. Despite grappling with his new life and the pain of waiting for loved ones to return from battle, as his own 'Daughter' once did for him, he becomes their hero. As they navigate their daily routine at the 'orphanage,' Willem and the girls learn the true meaning of familial bonds and what is worth safeguarding.
