In the distant future, Earth is covered by thick clouds, leaving the world trapped in endless winter and darkness. Most plants have died, and humanity survives by relying on the small amount of oxygen produced through “Tenka,” a technology that implants seeds into people near death and transforms their bodies into plants.
Toshiro Kamiya, a young man struggling with poverty and caring for his mentally ill mother, gradually loses hope as the harsh realities of life wear him down.
With nothing left to look forward to, he chooses to become a “Reika,” a plant born from a transformed human. He must decide whether to continue living as a human or abandon his suffering and begin a new life as a plant.