Haruaki Yachi is a high school boy and naturally resistant to curses. His father, Honatsu, sends him cursed instruments called "Worse" to try to break this. One day, Haruaki receives a black cube from Honatsu. During the night, he encounters a naked silver-haired girl stealing rice crackers. She is the human form of the black cube, an instrument of torture called "Fear in Cube". Haruaki and the girl "Fear" fight together against other Worse instruments and their owners using Fear's 32 mechanisms of torture.