Kaina of the Great Snow Sea: Star Sage

A world covered in an endless, ever-expanding sea of snow. People survive by clinging to the roots of massive trees scattered across the surface or by living high in the canopy, which stretches above the planet's atmosphere. When Kaina, a boy from the canopy, crosses paths with Ririha, a young woman from the surface, their encounter sparks a series of events that will reshape the world's destiny.