On a small, lonely island in Ivoire lives Ash, a Phantom who lost his life in battle, and Marona, who has the ability to communicate with Phantoms.

Marona makes her living as a Chroma, a person who accepts freelance work to solve problems for people. However, because of her abilities, the people call her the "Possessed."

Still, Marona stays optimistic and follows what her parents told her long ago: "Help people, and someday everyone will start to like you." Her goal is to save enough money to buy Phantom Isle, which she's currently renting. Like a subtle wave in the sea, the adventures of Marona and Ash are about to begin.