Set on mysterious Kaiden Island where abandoned people arrive. Nanakusa (Ryusei Yokohama) and Yuu Manabe (Marie Iitoyo) were childhood friends. Now, they are high school students and they meet again on Kaidan Island. They get involved in various cases. Movie is based on Kono Yutaka's novel about two childhood friends in a remote island – an island for discarded people.
