Shinpei Ajiro had been residing with the Kofune family and their two girls, Mio and Ushio, ever since the passing of his parents. After Ushio tragically drowns while attempting to save a young girl, Shinpei returns to his native island despite having left before to pursue his degree in Tokyo. His best friend reveals to him during the funeral that there were bruises around Ushio's neck, raising questions about how she died. Suspecting a murder, Shinpei reconsiders the previous events, but weird occurrences just keep happening. Mio is reminded of an old folktale about "Shadows," which may not be entirely made up, as a result of disappearing persons and other strange events. A person's impending death is supposedly predicted by a meeting with their Shadow. Facing the shadowy side of Hitogashima