In another world, an endless sea of snow engulfs the surface of the entire planet.People struggle to survive and live around the huge "Tree of Heavenly Track" - the branches of the giant tree towering into the clouds, penetrating the "sky film" above the sky.In this world gradually heading towards destruction, the turning point of fate quietly comes.The young man Kaina from the sky met Lilia, a girl from the ground world. Two souls that should not have intersections were closely connected between this frozen world, opening the prelude to changing the world.