C3: A school battle action & love comedy with ecchi elements. Yachi Haruaki 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 Fears 32 mechanisms of torture.