In a world covered in snow and lacking water, humanity teeters on the brink of extinction. The only hope lies in the legendary sage rumored to possess the knowledge to save mankind by creating water. Princess Ririha, from Atland, embarks on a perilous journey using an organic hot-air balloon to reach the pinnacle of an Orbital Tree, where salvation is said to await. At the Canopy, a mesmerizing expanse of ice, she encounters Kaina, one of the few remaining survivors, but not the one she sought. Stranded without a way back, Ririha finds an unexpected ally in Kaina, who craves exploration of the supposedly barren surface world. As Kaina delves into the conflict between Ririha's nation and the advanced Valghia, facing the dangers lurking on the surface, he realizes that their mission together is far more challenging than he ever envisioned.