A friendship ritual gone awry transports high school student Ayumi Shinozaki and her friends to an alternate reality version of a tragedy-stricken institution that stood on the site of their own school long ago. As the vengeful spirits of elementary school students threaten their lives and their sanity, their only hope of survival–much less escape–is to uncover the chilling details surrounding the murders of those trapped before them.
Mt. Hikami was once revered as a spiritual place. It housed a unique religion based on beliefs and customs of worshipping water as a deity and is said to have been a site of many gruesome incidents and mysterious phenomena. This mysterious and intertwined story follows three protagonists—Yuri Kozukata, Miu Hinasaki, and Ren Hojo—as each of them explores the ominous Mt. Hikami, a place where many came to die, and the secrets it hides.