Fifteen years earlier, a catastrophe devastated humanity, and today ferocious predatory beasts stalk the scarred terrain, threatening every survivor. In this chaos, a secluded compound protects children and raises them in calm. Yet when some learn of the world beyond their nursery's confines, their wonder for it slowly intensifies.
Out there, fledgling survivors Maru and Kiruko unite to seek a place called Heaven, each driven by personal motives. Bearing old wounds and hidden griefs, the pair yearn to uncover explanations for the suffering they've faced amid a world still in ruins. They carry memories of loss and unspoken truths, hoping that Heaven might hold the answers they desperately need. Their journey is fraught with danger, yet their resolve remains unshaken.