Moving to the mountain town of Jouga due to his father's job, 15-year-old Hiroshi Kuzumi and his family face the challenge of adjusting to a new environment. However, Hiroshi finds himself embraced with open arms by most of his schoolmates, making two friends in the form of his neighbor, Isuzu Tsumuhana, who is affectionately clingy, and Kaname Asagiri, who recently moved to Jouga. Initially, Hiroshi's new life seems like the perfect fit until people start disappearing. Although Hiroshi is told that the missing townsfolk have either transferred or moved away, he can't help but feel that something isn't right. Unbeknownst to him, masked figures led by a girl wielding a scythe roam the streets of Jouga at night under a red moon. Hiroshi is left to wonder, who are these figures, and is anyone in Jouga safe from their clutches?