Kaina of the Great Snow Sea
大雪海のカイナ
In another world, a Sea of Snow keeps growing and has swallowed the planet's surface. People struggle to survive around the routes of a giant Orbital Tree, whose branches spread into the Celestial Membrane high above the ground. Change comes to this dying world after Kaina, a boy from the Celestial Membrane, meets a girl from the surface named Ririha.
