Because of his father's work, 15-year-old Hiroshi Kuzumi and his family relocate to the mountain town of Jouga. While some teens might fret about fitting in or feeling out of place in a new setting, Hiroshi is greeted warmly at school by most of his new classmates. In fact, it appears they simply cannot get enough of him, and he quickly makes two friends: Isuzu Tsumuhana, his neighbor, who is clingy and overly affectionate; and Kaname Asagiri, who has also recently moved to Jouga. Overall, Hiroshi's new life seems fairly ordinary—until people begin to vanish. Hiroshi is informed that the missing townspeople have merely moved away or suddenly transferred, yet he cannot shake the suspicion that something is amiss. Meanwhile, in the dead of night under a red moon, masked figures led by a girl wielding a scythe stalk their prey through the darkened streets of Jouga. Who are they, and is any resident safe from their wrath?