Yachi Haruaki is a high school boy. He is naturally resistant to curses, and his father, Honatsu, sends him cursed instruments known as "Worse" so that he can break the curse. One day, Haruaki receives a black cube from Honatsu. That night, he encounters a naked, silver-haired girl stealing rice crackers. She is the human form of the black cube, a torture instrument called "Fear in Cube." Haruaki and the girl, 'Fear,' fight together against other 'Worse' instruments and their owners, utilizing Fear's 32 mechanisms of torture.