Rakan Sawa is an ordinary high school student living a solitary, quiet life while tending to his many lush plants. This tranquility is shattered when a foreign man and several dangerous creatures suddenly crash into his garden. The man immediately points his strange, plant-like weapon at Rakan, but his demeanor shifts completely after witnessing the weapon respond to Rakan's touch. The man, Chigusa, declares that Rakan is a precious "sanome," a person capable of cultivating plant life at will. As the last known sanome, Chigusa vows to protect Rakan at all costs and requests his assistance. Chigusa is a notorious outlaw who aims to destroy the "ayame," creatures that drain life from his dying world, including the current prince, who oddly looks exactly like Rakan. Rakan travels to Chigusa's desert world, which is populated by despondent people, strange creatures, spirits, and magic. Along the way, they gather more followers and supporters in their quest to restore greenery to the barren, decaying land.