Shinpei Ajiro is returning from Tokyo to his island home in Wakayama prefecture to attend the funeral of his childhood friend Ushio. Although Ushio supposedly died while saving a young girl from drowning, there were bruises around Ushio’s neck, making the exact cause of her death questionable. Meanwhile, doppelganger-like entities are supposedly haunting the island, and Shinpei keeps experiencing visions of a deceased Ushio asking him to save her younger sister Mio.