Yoshiki Tsujinaka's best friend Hikaru Indo went missing in the mountains and walked back into the village a week later looking, sounding, and remembering everything like himself. Six months on, Yoshiki still cannot shake the feeling that whatever came back is not actually Hikaru. Torn between the comfort of keeping their friendship as it was and the growing dread of what Hikaru might really be, Yoshiki keeps spending time with him anyway. This novelization adapts the ongoing horror manga of the same name.