A mysterious application named "Shireishi" begins to circulate throughout the town of Nishioka, claiming to put its users in contact with a ghost known by the same name. While seemingly harmless, a number of disappearances and reports of violent behavior begin to be linked to people who use the application. Many of the incidents center around Hikarimirai Academy, leading to the involvement of several students in the unfolding chaos.

As the threats facing the town become more real, Shireishi's involvement becomes harder to ignore. Whether they are haunted by a ghost or a twisted criminal, it is clear that the people of Nishioka cannot ignore this entity forever. Until someone acts against Shireishi, its terrorizing grip on the town cannot be released...