Yachi Haruaki, a high school student, possesses a unique immunity to curses, a trait inherited from his father Honatsu. To help him overcome curses, Honatsu sends him cursed tools known as 'Worse.' One fateful day, Haruaki is given a mysterious black cube by his father. That night, he encounters a silver-haired girl in human form who turns out to be the embodiment of the black cube, known as 'Fear in Cube,' an instrument of torment. Together, Haruaki and Fear join forces to battle against other 'Worse' instruments and their wielders, utilizing Fear's arsenal of 32 torture mechanisms.