Several young girls possessing unusual abilities, along with a train carriage that has been overtaken by a growing tree, are fighting for survival in a barren wasteland. In their pursuit of the last remaining sources of water, their daily battle for existence is disrupted by the unexpected arrival of Wakaba, a boy who only knows his own name. With determination, the girls and their newcomer set out on a treacherous journey through crimson clouds, in search of sustenance on far-off, hostile islands overrun by mechanical insects. The outcome of their quest hinges on their collective perseverance, alongside Wakaba's remarkable intelligence in comprehending the enigmatic Kemurikusa, which are radiant leaves with extraordinary powers. Apart from these girls, Wakaba, and the swarming predatory bugs, Kemurikusa represents the only existing sparks of vitality in this part of the world. What led to this catastrophic situation? Why are there abandoned structures with no indication of human habitation? To these queries, Wakaba and the girls can only turn to the Kemurikusa for answers.