Coco lives as the only resident of a vast mansion. She would be completely isolated were it not for her cherished black cat, Kuro. Despite Kuro's peculiar habits, the pair is inseparable and engages in lively adventures every day. Coco is lulled into happiness by these idyllic days and remains entirely oblivious to the terrifying reality surrounding her. For the rest of the townspeople, life is marked by dread and discomfort. They fear the dark forces encircling their town, yet they are also afraid of Coco and Kuro. Unaware of the circumstances, Coco continues her tranquil life with Kuro, but her period of blissful ignorance may soon draw to a close.